LITHIUM ION BATTERY FOR ELECTRONIC DEVICES
FIELD OF INVENTION:
The present invention pertains to electronic devices including electronic cigarettes or vaping
devices or inhalation devices. More particularly, the present invention pertains to a
novel Lithium battery for Electronic devices, preferably in Electronic cigarettes or vaping
devices or inhalation devices.
BACKGROUND OF INVENTION:
Electronic cigarettes or vaping devices or inhalation devices have become popular as
replacement products to cigarettes since they contain fewer toxic ingredients and the early
data indicates that they may be significantly safer than conventional cigarettes. The
conventional cigarette provided smoking experience by burning of tobacco wrapped in a
paper, and the smoke consisted of several constituents such as tar, aldehydes, polycyclic
aromatic hydrocarbons (PAH's), Carbon Monoxide (CO) , Benz-o-pyrene along with nicotine
vapor.
It has been known that smoke constituents such as tar, aldehydes, PAH's, CO and several
other compounds are harmful, and hence, product development efforts were directed at
providing nicotine vapor with minimal/no amount of tar, CO, and PAH's to the smoker.
Electronic cigarettes or vaping devices or inhalation devices use advanced batteries and the
batteries need to be recharged for further use after the dissipation of the power due to heating
of the liquid medium or can be designed for multiple uses with a single charging cycle.
Unlike conventional cigarettes, electronic devices, such as an electronic cigarette are complex
since the design requires controlled heating of liquids to generate an aerosol vapor for
sensorial satisfaction. There are several parts in electronic devices, especially e-cigarettes,
such as a Light emitting diode (LED) to indicate the action of the use of the device, puff
sensor to sense the air flow and activate vaping, electronic circuit consisting of several
components for controlling the function of the device, heater for heating the liquid and
creating an aerosol, liquid reservoir for storage of liquid sufficient for several vapes, and
filter/mouthpiece as interacting component with the user. Some or most of these parts require
power by way of charging device, preferably, battery. Some of them also contain
rechargeable pins for charging the battery. Current electronic cigarettes or vaping devices or
inhalation devices claim that the batteries will allow use of electronic cigarettes or vaping
devices (or inhalation devices) for a period about 12 to 24 hours of intermittent use, when
charged once and for about 5 min or longer in continuous use. In reality, they do not operate
due to the lack of energy density in the batteries employed in the electronic cigarettes. Hence,
the user is required to recharge the battery frequently, which is a cumbersome process. In
addition, consumers are not satisfied with the consistency of the aerosol volume since the
amount of energy supplied by the battery to the heater varies with the voltage and capacity of
the battery present at the time the consumer takes the puff. Battery capacity is defined as the
charge storage capacity and is the product of current (in Amperes, A, or in mA) that a battery
can deliver for a given amount of time (hour). The capacity of an electronic devices battery
can be chosen based on the design of electronic devices and can be anywhere from 80 mAh
to 2000 mAh at standard conditions of 25°C. Capacity of the battery, even when it is fully
charged, varies based on the quality of the battery and a poor quality battery may supply only
a fraction of the rated capacity of the battery. The energy supplied by the battery to the heater
will determine the temperature of the heater. Both the rate of heating and the maximum
temperature influence nucleation, generation and condensation of aerosol from an e-liquid,
temperature of the aerosol inhaled, and possible degradation of e-liquid carriers such as
propylene glycol and glycerine into harmful and toxic compounds.
In the case of an electronic device application, Li-ion battery supplies current to the heater
connected across its positive and negative terminals, and the voltage difference drives the
current flow to the heater. An appropriate level of terminal voltage must be available for a
heater (resistance) coil in an electronic device to heat and generate an aerosol. Therefore, the
operating voltage of the battery is an important parameter in aerosol generation. The voltage
decreases with usage of electronic devices (also known as discharge) and the drop in voltage
has an effect on the overall heating and aerosolization of the liquid as may be seen from the
following discussion.
The battery capacity of an electronic device varies based on several factors, including the
purity of the materials used in the construction of the battery; composition of the cathode
materials, material used as a separator; the materials used for anode; particle sizes and shapes
of the cathode and anode materials; crystallinity of the materials; conductivities of the
cathode and anode layers; current collectors (materials) employed in the construction of the
battery; additives added to increase the conductivity; coating techniques employed to coat the
cathode and anode materials; assembling techniques used to assemble the battery finally
techniques employed to roll all of the layers into a cylindrical configuration of desired length
and diameter, and cleanliness of the overall manufacturing area of the batteries.
In developing or selecting an electronic devices battery, it is important to minimize the
internal resistance of the battery in order to maximize the terminal voltage. An increase in
internal resistance of the battery leads to a voltage drop and would lead to a lower terminal
voltage, which is incapable of generating a desired aerosol. The terminal voltage of any
battery may be measured by formula (1) and is decreased by the current flowing (I) through
the Li-ion battery at a given point of time multiplied by the internal resistance of the battery
(Ri). The battery terminal voltage (V battery) equal to
V battery = V0 - (I x Ri) Formula (1)
Where, V0 is the open circuit voltage and is defined as the maximum possible voltage.
The open circuit voltage (V0) of the current electronic devices batteries is generally about 4.2
V. As may be noted from formula (1), it is desirable to select/develop a battery with low
internal resistance in order to prevent a significant voltage drop while drawing a large current
flow to generate an aerosol. Many factors contribute to the internal resistance in a Li-ion
battery. The cut-off voltage of Li-ion batteries is about 3.0V implying that the current may be
drawn until the voltage is 3.0V and drawing current below 3.0V may lead to over-discharge
of the battery in use.
In an electronic device application, the current discharge rate (referred hereafter as discharge
rate) is determined based on the capacity of the battery, resistance of the heater and the
voltage of the battery. Typically, batteries operate very well at lower discharge rates and
perform poorly at high discharge rates. Unlike other applications, electronic devices require
high rate of discharge for heating of the liquid and the generation and inhalation of desired
aerosol. However, the discharge rate may differ between various electronic devices. The
discharge rate of an e-cigarette may be selected and is considered akin to a cigarette within
the puff duration of 2 to 4 sec. In a conventional cigarette, smoke aerosol is generated from
tobacco immediately upon puffing due to the presence and movement of pyrolysis and
combustion zones. To simulate the conventional smoking behavior, The discharge rates in
electronic devices may be selected to be in the range of 5C to 20C, based on the resistance
of the coil, where C is referred to as the rate of (charging or) discharging.
For a given heater, battery capacity and the terminal voltage of the battery will determine the
number of puffs that a consumer is able to puff on an e-cigarette. Typically, a smoker who
consumes a pack of about 20 cigarettes per day is able to obtain about 160 puffs of 2 to 3 sec
puffs. This is generally equivalent to about 320 to 480 sec puff duration, implying that a Liion
battery should allow the smoker to draw the required current lasting about 5.33 to 8 min.
The terminal voltage of the battery and the resistance of the heater along with contact
resistance will determine the current required to heat the heater to a desired temperature.
Battery capacity may be determined based on the current and the discharge duration as given
by formula (2):
Li-ion battery capacity (Ah) = Discharge duration (h) X Current (A) - Formula (2)
For example, an electronic device designed for a 2 sec puff duration of about 160 puffs with
a current of 1.2 A requires a battery with a theoretical capacity of about 106 mAh, whereas a
puff duration of 3 sec requires a battery with a theoretical capacity of about 160 mAh. On
the other hand, if the puff duration is increased to about 3 sec with a 106 mAh capacity
battery, the current drawn will decrease from 1.2A to 0.8 A. Increasing the battery capacity
to about 240 mAh capacity allows a user to draw a current of 2.7 Amp at about 2 sec puff
duration, and 1.8 Amp at about 3 sec puff duration. If a consumer increases the puff duration
to about 5 sec, the consumer may draw about 1 Amp current only even with a 240 mAh
battery. Therefore, it is important to design a Li-ion battery for electronic devices based on
the current discharge, the puff duration of the average user and the number of puffs required.
The voltage and the charge capacity determine the amount of electrical energy stored in the
battery. Li-ion batteries are typically operated with a terminal voltage of about 3.6 V. Energy
stored in a battery is given by Formula (3),
Energy (watt-hour) = Li-ion battery capacity (Ah) x Voltage (V) Formula (3)
For a battery with a 100 mAh capacity, Energy = 0.1 Ah X 3.6 V = 0.36 Wh
For a battery with a 240 mAh capacity, Energy = 0.24 Ah X 3.6 V = 0.86 Wh
Therefore, it is important to design and use an advanced Li-ion battery for electronic devices
with higher capacity and higher terminal voltage than the Li-ion batteries of prior art and
prior use.
The power required to generate an aerosol in electronic devices may be increased by
increasing the current supplied to the heater at a given voltage since it is a product of voltage
and current.
Hence, for instance, if one would consider a terminal voltage of 3.6 V, a capacity of 100
mAh, and a puff duration of 3 sec (with a discharge time of 8 min for 160 puffs):
Discharge current = Li-ion battery capacity (Ah)/Discharge duration (h) = 100 mAh/0.133=
0.75 Amp
Power = Voltage (V) X Current (A) = 3.6 X 0.75 = 2.7 Watts
The user determines the puff duration and unlike smokers of conventional cigarettes,
electronic devices users tend to draw puffs of 3 sec or higher, and the design of the battery for
electronic devices needs to take these factors into account.
The challenge of designing a battery of desirable parameters includes obtaining a battery with
desired configurations, such as diameter and length. For instance, in an e-cigarette, the length
and the diameter may be required to mimic normal cigarettes, and the configuration would
also determine the capacity of the battery. Once the capacity is selected, it is important to
utilize as much battery capacity as possible for generating an aerosol in a disposable battery
or a rechargeable battery. In practice, the entire battery capacity cannot be used to heat the
heater and generate aerosol. Although Li-ion batteries have the best depth of discharge (% of
utilization) of close to 80 to 90%, the terminal voltage decreases with the usage of the device,
and this will influence the energy supplied to the heater and the quality and quantity of
aerosol generated. In other words, the open circuit voltage and the terminal voltage of the
battery decrease as the battery capacity decreases with each use.
Furthermore, discharging and charging of Li-ion battery at high currents is generally not
considered safe since it will decrease the life of the battery and is known to cause mechanical
or structural damage to the battery. Li-ion battery may be charged using constant current,
constant voltage or by both constant current and constant voltage. Charging and discharging
current rates may also be specified by the length of the time in which a given battery would
be charged or discharged and the rates are indicated as C-rating.
C-rating value is defined as in formula (4):
C-rating (Amperes) = Battery capacity (Ah)/Number of hours for full charge or discharge (h)
Formula (4)
Based on the prior art analysis, it may be noted that electronic devices as currently available,
do not have a battery that satisfies the user requirements. Furthermore, the batteries and the
electronic circuits as discussed, in the prior art and in prior use, do not take these factors into
consideration and therefore, do not provide effective vaping capabilities. Hence, there is a
need for an improved Li-ion battery for effective use in electronic devices.
The battery of prior art and prior use comprises an anode (negative electrode), a cathode (a
positive electrode), current collectors and an electrolyte as a conductor as depicted in Figure
2. Typically, the cathode is a metal oxide material containing lithium in a lithium ion battery
and the anode is graphitic carbon. There is a transfer of electrons between the anode and
cathode during the charge and discharge cycles.
In the case of prior art and prior used Lithium batteries, the cathode material is generally
found to be lithium Cobalt Oxide and the anode material is based on graphitic carbon. The
reported practical capacity of lithium ion batteries with Lithium Cobalt Oxide as the cathodic
material and graphic carbon as an a anode is about 137 mAh/g when cycled in the voltage
range 3-4.25 V, even though the theoretical capacity is estimated to be as high as 273.8 mA.
h/g.
Therefore, to obtain higher capacities, one has to charge the cells to high voltages (4.5 V),
which is currently not practicable or feasible. Furthermore, there have been reports of
explosion of the Li-ion batteries of electronic devices and they pose a great risk to the
consumers. The nature of the materials employed in the construction of the battery and
impurities present in the assembly and manufacturing area lead to thermal runaway and short
circuit causing explosion of the batteries.
Hence, there is a need to have a lithium ion battery, with improved factors as discussed
herein. Moreover, the consumer product nature of a disposable electronic devices product
requires that the overall cost of the battery be reduced by finding alternate materials for the
cathode, the separator, the anode and the electrolyte. In addition, lithium ion battery
technology is constantly in need of innovative developments such as high energy density,
operate safely over a wide temperature range of interest, high terminal voltage, ability to
safely charge and discharge at high rates of charge/discharge for several hundred cycles
without loss of capacity, and also replace or reduce the toxic and strategic cobalt element
from the battery composition.
Analysis of current Li-ion batteries for their materials chemistry and performance using a
variety of experimental techniques such as X-ray diffraction, IR spectroscopy, Raman
spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, cyclic
voltametry, impedance spectroscopy charge and discharge behavior at different discharge
rates, thermal runaway and safety tests indicate that most of the electronic devices batteries
employed today are based on Lithium cobalt oxide (LiCo02) as cathode, carbon as an anode
and a polypropylene polymer as a separator material. The electrolyte material used is a liquid
electrolyte based on Lithium salts mixed with an organic binder. The present invention
discloses a novel lithium ion battery for use in electronic devices including vaping devices or
inhalation devices or e-cigarettes based on an understanding of the limitations and
functioning of the current batteries. The novel battery of the present invention provides
higher capacities for a predetermined configuration and advantageous cycling efficiency and
thereby would be convenient for the end user of an electronic device. The battery of the
present invention may advantageously be used in an electronic devices, disclosed in co¬
pending Indian provisional applications having priority numbers of 140/DEL/2014,
141/DEL/2014 and 137/DEL/2014, all dated, which is considered as a part of the present
invention and read in conjunction.
BRIEF DESCRIPTION OF FIGURES:
Figure 1 depicts an embodiment of the present invention being electronic cigarettes.
Figure 2 depicts a general schematic diagram of the Lithium-ion battery. Figure 2(a) depicts
the discharge mechanism of the battery and figure 2(b) depicts the charging mechanism of the
lithium ion battery.
Figure 3 depicts the structure of fullerene, carbon nanotube and graphene
Figure 4 depicts the cycle number Vs discharge capacity curve of the lithium ion battery of
present invention at 1C charge/0. C discharge rate with initial charge capacity of the present
invention 313mAh.
Figure 5 depicts the cycle number Vs discharge capacity curve of the lithium ion battery of
the present invention at 1C charge/ IOC discharge rate with initial charge capacity of
219mAh.
Figure 6 depicts the cycle number Vs discharge capacity curve of the Lithium ion battery of
the present invention at C charge/5C discharge rate with initial charge capacity of 240mAh.
Figure 7 depicts the cycle number Vs discharge capacity curve of the battery of present
invention at 1C charge/lC discharge rate with initial charge capacity of 257mAh of the
Lithium-ion battery of the present invention.
Figure 8 depicts cycle number vs. discharge capacity curve of V type commercial e-cigarette
battery charged at 1C and discharged at 1C.
Figure 9 depicts cycle number vs. discharge capacity curve of V type commercial e-cigarette
battery charged at 1C and discharged at IO C.
Figure 10 depicts cycle number vs. discharge capacity curve of G type commercial ecigarette
battery charged at 1C and discharged at 1 C.
Figure 11 depicts cycle number vs. discharge capacity curve of G type commercial ecigarette
battery charged at 1C and discharged at IOC.
Figure 12 depicts the thermal runaway behavior of a G type commercial e-cigarette battery.
Figure 13 depicts the short circuit behavior of G type commercial e-cigarette battery.
Figure 14 depicts the short circuit behavior of V2 type commercial e-cigarette battery.
Figure 15 depicts the short circuit behavior of V type commercial e-cigarette battery.
Figure 16 depicts the thermal runaway behavior of the Lithium ion battery of the present
invention
Figure 17 depicts the short circuit behavior of the Lithium ion battery of the present
invention.
BRIEF SUMMARY OF INVENTION:
The present invention relates to a novel lithium ion battery. The novel battery of the present
invention discloses the novel chemical materials and/or compositions for construction of
anode and cathode and electrolyte of the said battery. The battery of the present invention is
capable of being used as a disposable battery and as a rechargeable battery designed
specifically for electronic devices.
DETAILED DESCRIPTION OF THE INVENTION:
The present invention relates to a novel lithium ion battery.
The novel battery of the present invention discloses the novel chemical materials and/or
composition for construction of anode and cathode of the said battery.
The novel battery of the present invention discloses advanced manufacturing techniques for
the construction of the said battery.
The novel battery of the present invention discloses that the battery is safe from a thermal
runaway and short circuit dangers.
The novel battery of the present invention provides higher capacities and advantageous
cycling efficiency and thereby would be convenient for the end user. The battery of the
present invention is capable of being used as a disposable battery and as a rechargeable
battery.
The present invention further improves the performance of the anodic material by adding
nitrogen doped carbon nanotubes, fullerenes and graphene as part of the anode preparation.
Such structures are depicted for ready reference at Figure 3.
The improved lithium ion battery for electronic devices of the present invention comprises;
a . a cathodic material;
b. an anodic material;
c . an electrolyte;
d. a separator;
e. current collectors;
wherein, the said battery has a charging capacity of 160 to 190 mAh/g; wherein, the said
battery has a potential window of 3 to 4.5 v; wherein, the said battery has a discharge rate of
10 to 15 times the battery capacity and is capable of cycling for 300 to 500 cycles.
The battery of the present invention is capable of being used in an electronic device. The
electronic device includes vaping devices, inhalations devices, e-cigarettes, portable charging
case (PCC) packs, accessories of electronic devices and the like.
A preferred electronic device of the present invention is an e-cigarette.
The E-cigarettes or vaping devices or inhalation devices of the present invention may be
illustrated by means of a Figure 1. The E-cigarettes or vaping devices or inhalation devices of
the present invention comprises of a housing ( 115). One end of the E-cigarettes or vaping
devices or inhalation devices comprises a Light Emitting Diode (LED) ( 111) which is
covered by a cap, which is placed or embedded at the tip end of the E-cigarettes or vaping
devices or inhalation devices. The LED cap may be designed to, fit and/or glued inside the
housing of the E-cigarettes or vaping devices or inhalation devices ( 115). The LED cap may
be structurally designed in such a way that it may include one or multiple inlet holes (121) to
allow air to enter the housing when the user would inhale from the mouth end (120).
It is preferable to provide a single or multiple light emitting diode ( 111) or any other light
device configured in the LED cap ( 111) to simulate the burning of the tip of E-cigarettes or
vaping devices or inhalation devices. The light element may be configured so as to vary the
intensity of the light device based on the amount of air flow between the two ends being
(120) & (121). LED may be a separate device or part of sensor or controller. The cartridge
may be an absorbent material ( 117) located inside the filter section (140), within the housing
( 1 15). The absorbent material may be selected from the group comprising polyester, wool,
cotton or porous ceramic, porous metallic or porous inter-metallic or any other absorbent
material and may be shaped or roll to be fitted inside the filter section (140) within the
housing ( 11 ). The absorbent material may be porous, with inter connected porosity and such
porosity aids in the storage of the liquid. The e-liquid may directly be present in the cartridge
without any absorbent material. The aerosolization of the e-liquid solution may be effected by
the heating element ( 1 18) and the heating element may be placed or embedded near the
cartridge ( 117) in the filter section (140) within the housing ( 115). The liquid may be
transported to the heating element by surface tension and capillary effect and this may be
further enhanced by a mechanism, such as a wick (126), for transport of liquid from cartridge
( 117) to the heater ( 118). An insulating sleeve ( 116) covers the heating element to insulate
the cartridge ( 117) from heater ( 118). The insulating sleeve ( 116) may be formed of a
thermally insulating polymeric fiber. The sleeve may ( 116) also serve as a means to provide a
flow passage to the aerosol that is released from the heater ( 118) to exit from the outlet hole
(120). The mouth piece of filter cap ( 119) is located at the opposite end of the E-cigarettes or
vaping devices or inhalation devices (i.e., opposite to the LED cap ( 1 1)). The mouth piece
( 119) is designed in such a manner that it has an outlet hole (120) where user can inhale the
aerosol generated by the E-cigarettes or vaping devices or inhalation devices.
The device also comprises of a display unit or a communication device (122), which may be
used by the user to change and monitor the various settings and state of E-cigarettes or vaping
devices or inhalation devices.
A sensor (125) is connected to the controller ( 112) and the communication device (122). The
sensor (125) may be individual or a group of sensors, preferably a group of sensors. The
sensor (125) may measure the air flow, temperature change, pressure change or any other
physical or electrical parameters. The sensor may send and receive signals form ( 12) and
also communicate to the communication device (122) such as a display. Communication
device would convert input signals to alpha numeric characters and displayed in the
communication device (122). The display may also be through light signals.
The power source ( 114) is designed to power the heating element ( 18), the LED situated in
LED cap ( 111), the communication device (122) and the sensor (125) and any other device
( 1 15) which requires power for operation. The controller ( 12) is placed or embedded in the
power unit section (130) and is powered by the power source ( 14). The controller may be
configured to control and monitor the heating element ( 18), the power source ( 1 14),
communication device ( 1 12), sensor (125), LED. The E-cigarettes or vaping devices or
inhalation devices may also comprise of electrical insulating material ( 1 13) or (123) that may
be provided to the power source ( 114) at both terminal ends to prevent short circuit. The
material used may be any type of insulation tape or soft insulation pads, insulating gel or any
other insulating material or liquid repellent coating. An insulation material may also be used
to prevent short circuit of electric components.
The partition (124) between the power unit section (130) and the filter section (140) is such
that it physically supports the heater terminal wires and insulating sleeve ( 116). The partition
(124) may be made up of any material, which prevents the flow of the liquid from one section
to another.
The various components or parts of E-cigarettes or vaping devices or inhalation devices may
be constructed of suitable materials such as plastic, wood, glass, metal, ceramic, intermetallic,
or composites thereof. These materials may be coated by a variety of chemical
deposition techniques and physical deposition techniques such that the outer tube material
may be aesthetically pleasing to the user and provides structural integrity and thermal
insulation.
The battery of the present invention is capable of being used in other devices and the concept
may be extended to Lithium ion batteries being used elsewhere.
Accordingly, the present invention discloses novel lithium ion battery.
A lithium ion battery operates by reversibly passing lithium ions between a negative
electrode (sometimes called the anode) and a positive electrode (sometimes called the
cathode). The negative and positive electrodes are situated on opposite sides of a microporous
polymer separator that is soaked with an electrolyte solution suitable for conducting lithium
ions. Each of the negative and positive electrodes is also accommodated by a current
collector. The current collectors associated with the two electrodes are connected by an
interruptible external circuit that allows an electric current to pass between the electrodes to
electrically balance the related migration of lithium ions (See Figure 2).
The Figure 2 is a schematic illustration of one embodiment of a lithium ion battery (1) that
includes a negative electrode (2), a positive electrode (4), a microporous separator (6)
sandwiched between the two electrodes (2), (4), and an interruptible external circuit (8) that
connects the negative electrode (2) and the positive electrode (4). Each of the negative
electrode (2), the positive electrode (4), and the microporous separator (6) may be soaked in
an electrolyte solution capable of conducting lithium ions. The microporous separator (6),
which operates as both an electrical insulator and a mechanical support, is sandwiched
between the negative electrode (2) and the positive electrode (4) to prevent physical contact
between the two electrodes (2), (4) and the occurrence of a short circuit. The microporous
separator (6), in addition to providing a physical barrier between the two electrodes (2), (4),
may also provide a minimal resistance to the internal passage of lithium ions (and related
anions) to help ensure the lithium ion battery (1) functions properly. A negative-side current
collector (2) and a positive-side current collector (4) may be positioned near each other to
collect and move free electrons to and from the external circuit (8).
The lithium ion battery (1) may support a load device (12) that can be operatively connected
to the external circuit (8). The load device (12) may be powered fully or partially by the
electric current passing through the external circuit (8) when the lithium ion battery (1) is
discharging. The electric current passing through the external circuit (8) may be harnessed
and directed through the load device, such as an electronic cigarette or a vaping device or
such (12) until the intercalated lithium in the negative electrode (2) is depleted and the
capacity of the lithium ion battery (1) is diminished. The lithium ion battery (1) may be
charged or re-powered by applying an external power source to the lithium ion battery (1) to
reverse the electrochemical reactions that occur during battery discharge. During the process
of charging, the external power source extracts the intercalated lithium present in the positive
electrode to produce lithium ions and electrons. The lithium ions are carried back through the
separator by the electrolyte solution and the electrons are driven back through the external
circuit, both towards the negative electrode. The lithium ions and electrons are ultimately
reunited at the negative electrode thus replenishing it with intercalated lithium for future
battery discharge. A lithium ion battery, or a plurality of lithium ion batteries that may be
connected in series or in parallel, may be utilized to power and charge an associated load
device. The ability of lithium ion batteries to undergo such repeated power cycling over their
useful lifetimes makes them an attractive and dependable power source for a rechargeable
electronic device. The charge and discharge capcity of the device may be understood from
from Figures 2 (a) and Figures 2(b).
In an embodiment, the present invention discloses a lithium ion battery component, wherein
the cathode is doped with transition metal cations and/or with non-transition metal cations,
and anode is based on carbon in the form of a sheet of graphitic particles embedded with
highly conducting carbon fibers, fullerenes, carbon nanotubes, graphenes etc. (Figure 3a, 3b
and 3c)
The present invention further discloses that electrolyte can be a liquid electrolyte consisting
of an ionic liquid such as (LiPF6, LiBF4, or LiC104) mixed with an organic carbonate liquid,
a liquid polymer or a gel electrolyte.
The present invention further discloses that electrolyte need not be a liquid material and can
be solid polymeric material comprising Lithium salt in addition with lanthanum, stannum and
germanium, zirconium, tantalum and titanium or mixtures thereof.
The electrolytic material of the present invention is such that it has higher conductivity than
prior art and prior used materials.
The lithium ion battery of the present invention comprises an electrolytic material. The
electrolytic material may be a liquid, and may be selected from an ionic liquid including
LiPF6, LiBF4, LiC104, organic carbonate liquid, a liquid polymer or a gel electrolyte or
mixtures thereof or a solid electrolyte and may be selected from a polymeric material,
including Lithium salt in conjunction with lanthanum, stannum and germanium, zirconium,
tantalum and titanium or mixtures thereof.
The Lithium battery of the present invention generally consists of an anode and a cathode.
The requirement for high specific capacity generally restricts choices to compounds
containing first-row transition metals (usually Mn, Fe, Co, and Ni) and compounds with
crystal structures which permit passage of Li - ion during charging and discharging processes
without any degradation of the cathode material. Typical crystal structures of the cathode
materials are layered structures, spinel structures along with olivine structure. The inorganic
layer of the compounds of the present invention may be selected from group comprising of
manganese dioxide, vanadium oxide, titanium disulfide, cobalt oxide, nickel oxide,
molybdenum sulfide or mixtures thereof, and their composites selected from the group of
Lithium Cobalt Oxide, Lithium Manganese Oxide, Lithium Iron Phosphate, and Lithium
Nickel Manganese Cobalt and Lithium Nickel Cobalt Aluminum Oxide.
The cathodic material of the present is selected from the group comprising lithium cobalt
oxide, lithium iron phosphate, lithium manganese cobalt oxide, lithium nickel cobalt
Aluminium oxide or mixtures thereof; and the transition metal content is in the range of 0.05
to 0.35 w/w of the cathode.
The cathode of the present invention is doped with at least single layer of transition metal
cations or with non transition metal cations or both. The transition metal ions of the present
invention may be selected from the group comprising Ti, Zr, Mn, Ni, Fe, Cu. These transition
metals are capable of exhibiting multiple oxidation states, The non transition metal cations
may be selected from the group comprising Al, Sn, Ga, Mg.
Many techniques may be employed for the synthesis of cathode materials - such as solid state
or wet chemical techniques such as co-precipitation, solution based combustion synthesis and
sol-gel techniques. The Solution chemistry technique is preferred in the present invention, so
as to obtain desired purity, chemical homogeneity and small particle size, factors important
for the battery capacity. The solution chemistry based on co-precipitation of hydroxides,
acetates, nitrates, sulphates, sulfites, phosphates, carboxylates, carbonates, and citrates is
preferred. Synthesis of mixed transition metal oxides by the above procedures followed by
their decomposition are used advantageously in the present invention for preparing a cathode
material. Without being limited by theory, the present invention, surprisingly, discloses the
use of solution techniques for the synthesis of cathodic materials. While decomposition of the
salts may be carried out, using a variety of techniques in a commercial scale, high through put
salt decomposition techniques that allow programmable and controllable rate of heating are
preferred over conventional batch heating techniques. Preferred techniques for salt
decomposition to obtain mixed oxide cathode materials of high purity and small size include
advanced fluidized bed decomposition techniques and multi-capillary aerosol spray
decomposition techniques. Advanced fluidized bed techniques allow continuous
decomposition of transition metal oxide salts with excellent thermal transfer due to uniform
flow characteristics in a fluidized bed and ability to continuously transfer the nucleated
cathode material of desired particle size to a storage chamber. Multi-capillary aersosol spray
decomposition techniques operates under the principal of spraying of salt liquid using
multiple capillaries at very high flow rates into an aerosol form in a heated chamber such as a
reactor and then transferring the nucleated cathode material of desired size to storage
chamber such as a reactor and then transferring the nucleated cathode material of desired
shape to a storage chamber. The above techniques provide small size and highly pure cathode
materials due to low resistance times in thermal reactors and yet provide high manufacturing
throughput for the synthesis of mixed oxide cathode materials
In another embodiment, the present invention envisages a method in which the particle size
of the metal dopants may be optionally reduced before or after the doping. The particle size
may vary from nano size to micron range, and preferably, distributed enough to obtain
excellent packing characteristics with good density, which would lead to desirable
conductivity. If the particle sizes are nano or sub-micron, spray drying techniques may be
used as part of processing techniques. Other industrial processes may be employed such as,
spray drying, , microwave heating, and any means of thermal decomposition by which a
homogenized material can be heated in a controlled manner in a semi-batch or in a
continuous process. Reaction temperatures can be obtained with the help of
thermogravimetric analyzer and differential thermal analysis. The nature of the desired
compound and completion of the reaction may be determined by X-ray diffractometry along
with Infrared and Raman spectroscopic techniques. The ratios of transition metal oxides in
the material may be determined by chemical means, Energy Dispersive X-ray Analysis, Xray
Flourescence and Wavelength Dispersive Spectrometry. The layered structure and the
crystal structure of the transition metal oxides can be determined by transmission electron
spectroscopy. Particle size analyser and small angle scattering techniques may be used to
determine the particle size.
The shape of the particles of the present invention may be spherical, rods or fibers, platelets
to elongated particles with different aspect ratios. Typically, particles are of spherical shape
in nature and other shapes can be obtained by special solution processing or milling
techniques. The milling may be done in wet or dry state.
In another embodiment, the present invention provides a high performance cathode (positive
electrode) of lithium cobalt oxide doped with layers of magnesium (non transition metal) and
copper (transition metal) to provide high conductivity and structural stability to lithium cobalt
oxide electrode for providing high performance to lithium ion battery with graphite anode,
embedded with fullerenes, carbon nanotubes and other conducting materials
The anode of the battery of the present invention is constructed of a material which may be
selected from the group comprising graphite, coke, coal, tar pitch, preferably graphite. Even
though carbon has the same molecular weight as natural graphite, graphite tends to be much
purer with less impurities and exhibits higher electrical conductivity. Graphite may be
selected from natural graphite such as Srilankan graphite or obtained from graphitization of
polyacrylonitrile material.
The present invention includes within its scope the use of natural graphite or a synthetic or
mixtures thereof. The nature of the graphitization can be determined based on an x-ray
diffractometer or a transmission electron microscope or instruments thereof.
The anodic material of the present invention is selected from the group comprising graphitic
carbon, carbon nanotubes, fullerene and graphene and mixtures thereof.
The present invention also envisages the use of a reduced material for the construction of the
anode. The anodic material, in addition, may further comprise of materials, selected from the
group comprising nickel, aluminum, tin, germanium and lead or mixtures thereof, which
would enhance electrical conductivity of the anodic material. The anodic materials may be
present either in their oxidized or un-oxidized state.
In yet another embodiment, the present invention discloses a process for construction of the
battery of the present invention. The battery of the present invention comprises an assembly
of the positive electrode, negative electrode, and solid electrolyte as described hereinbefore.
The fabrication of the battery of the present invention may be carried out by diverse method.
Since electronic device disclosed as part of this application requires current discharge at high
rates along with high current density, an improved anode is needed over the current anode
material available in prior art and prior use based on carbon, whether it is hard carbon,
graphitic carbon or a carbon based on pyrolysis of petroleum based compounds. In addition
to the crystal structure of the carbon, purity, particle size, and shape also a play role in
achieving the electrical conductivity and the theoretical capacity of carbon. Hence, graphite is
currently used as an anode with a theoretical capacity of 372 mAh/g. Carbon nanotubes and
fullerenes can be added to enhance the conductivity of the traditional graphitic particles. The
building block for all forms of carbon such as graphite, fullerenes, carbon nanotubes and
graphene is carbon atoms. Packed in honeycomb lattice, fullerenes, carbon nanotubes exhibit
remarkable properties such as high Young's module, high fracture strength, excellent
mobility for charge carriers and very high thermal conductivity as compared to conventional
graphitic carbon material.
The anode may be further improved by selecting another material with much higher
theoretical capacity than carbon and creating a composite structure containing conventional
carbon based anode along with an improved anode material. For instance, the theoretical
capacity of pure Tin is around 950 to 9904 mAh/g, which is three times that of the graphite
anode (372 mAh/g), based on the end lithiated phase Li4.4Sn. In addition, theoretical
capacity of silicon is 4200 mAh/g and is more than ten times that of graphite.
Since, both tin and silicon are reported to undergo huge volume expansion upon cycling,
when used as a part of Lithium ion battery for instance, silicon exhibits volume expansion of
about 400% during insertion and extraction of Li-ion corresponding to charging and
discharging of the Li-ion batteries, it is preferred to use the said materials in conjunction with
graphite by creation of an engineered structure of anode.
Tin may be in its native or oxidized stage and silicon may be used in its native state, with
preferably reduced particle size, such as nano or sub-micron size. Other compounds such as
transition metal silicides, nitrides, carbides and phosphides along with intermetallic
compounds may be employed as a part of anodic structure to improve the performance
characteristics of Li-ion battery.
The novel battery of the present invention discloses an improved cathode in conjunction with
the existing anode materials used in a conventional Li-ion battery and or with an advanced
anode material as described in this application. The improved cathode of the present
invention consists of the cathodic material with transition metal cations and/or with nontransition
metal cations along with or without carbon nano tubes fullerene and grapheme.
Cathode and anode of a Li-ion battery can be manufactured by using small size powders of
the same and mixed with additives and binders such that a paste is obtained. The material
may also be obtained as a slurry or as an ink. The paste may then be extruded using either a
single screw or twin screw extruder or could be tape cast or doctor bladed or roll compacted.
The quality, consistency and speed of operation and the manufacturing principles underlying
each one of the above methods are different but all the above techniques can be employed
successfully to construct a Li-ion battery on Copper and Aluminium current collectors.
The collector material of the present invention may be selected from the group comprising
Aluminum or Copper, which may further comprise thin coatings of metal or inter-metallic
compounds selected from the group comprising iron, nickel, titanium, copper.
The separator material may be any one of polyethylene, polypropylene, fluorinated co
polymers with at least one hydroxyl group. Additive manufacturing may be employed to
construct a Lithium ion battery using appropriate materials discussed above.
In addition to the above, 3D printing could be employed with the currently available 3D
printers, using cathode and anode materials or their pastes to build a Li-ion battery by
placing the current collectors and separator at an appropriate time of printing. Heating of the
pastes,( to evaporate liquids and decompose binders) may be accomplished by a variety of
methods by which controlled heating can take place without creating blisters or holes in the
thin layer of cathode or anode. 3D printing of a Li-ion battery may be accomplished using
either a single 3D printer or a series of 3D printers. Electrolyte may be sprayed at an
appropriate time of the manufacture of the cell. 3D printing allows incorporation of
grapheme, fullerene and nanotubes.
In another embodiment, the present invention discloses a process for preparing the lithium
ion battery, comprising the steps of;
1. preparation of the anodic material;
11. preparation of the cathodic material;
in. preparation of the electrolytic material;
IV. preparation of the separator ;
v. preparation of the collector;
VI. assembly of components of steps (i) to (v)
The anodic material may be prepared by mixing powders of carbon along with carbon
nanotubes or fullerene or graphene mixed with conducting materials and may then cast into
an anode by techniques discussed herein.
The cathodic material may be prepared by the decomposition of salts prepared by solution
chemistry techniques in a reactor.
The battery may be assembled by placing all components such as the cathode, anode,
collector material, electrolyte, separators and collectors.
The charge management of the battery of the present invention may be controlled by an
integrated circuit and the energy management may be accomplished by providing a sense
resistor to measure the current in and out of the battery and calculated the remaining energy
of the battery. The energy management may be controlled by a programmable electronic
controller.
The said battery of the present invention may be protected from thermal runaway and short
circuit by incorporating a protection circuit such that the battery operates within the desired
voltage and current limits.
The said battery of the present invention may be charged and discharged safely with a charge
management integrated circuit.
The charging capacity of the battery of the present invention is in the range of 110 to 220
mAh/g, preferably in the range of 130 to 200 mAh/g, more preferably in the range of 140 to
190 n Ah g.
The potential window of the battery of the present invention is the range of 3.0 to 4.5 V.
The discharge rate of the battery of the present invention is in the range of 0.1 to 15 C,
preferably, 1 C to 13C, more preferably 5C to 12 C. The charging rate of the battery of the
present invention is in the range of 0.1 to 5 C, preferably, 1 to 3 C.
The thermal runaway associated with short circuit is prevented by an electronic circuit in the
present invention.
The battery of the present invention may be suitably charged and used as part of disposable
electronic devices or used as a rechargeable battery and disposed only after several hundred
cycles of recharging.
The novel re-chargeable battery of the present invention maybe used in devices meant for
vaporizing a liquid for sensorial enjoyment or for vaporizing liquid meant to be used as
medicament for therapeutic purposes or for vaporizing liquid meant for providing
fragrance, i.e., perfumes.
The battery of the present device may be used for electronic devices, selected from the group
comprising electronic cigarettes, portable charging packs, vaping devices, inhalation devices,
preferably electronic cigarettes.
Without being limited by theory, it is submitted that the cathode material of the present
invention, will increase the charging voltage of the lithium battery of the present invention
and the discharge capacity to at least about 190 mA. h/g from about 130 mA. h/g.
ADVANTAGES OF THE PRESENT INVENTION:
1. The battery of the present invention has increased charging voltage and decreased
discharge capacity, thereby enabling wider time gaps between the charging cycle.
2. The advanced cathodic and anodic materials exhibit higher conductivity, therefore
enabling decreased time cycle in charging the battery.
3. The battery of the present invention may be recharged for several more cycles than
the battery of the prior art before disposing it off.
It may be understood by a person skilled in the art that the present invention is accompanied
by figures. The figures form a part of the invention. The figures encompass the embodiment
as illustrated in each figure. It is understood by a person skilled in the art that other variations
of the device and combinations thereof are envisaged within the scope of the invention. The
method of performing the invention using the device is also envisaged within the scope of the
said invention.
EXAMPLES:
The following examples are indicative and are provided herein as a means of illustration but
are not meant in any way to restrict the effective scope of the invention.
EXAMPLE 1: Preparation of anode according to present invention
The anode material of the present invention is prepared by taking graphitic carbon powder
and mixed with a polymeric binder along with additives such as carbon nano tubes, fullerene,
graphene, carbon fibres in the ratio of 2% by weight. A slurry based paste is prepared and the
paste is deposited on a copper current collector, dried to obtain the anode.
EXAMPLE 2: Preparation of cathode according to present invention
Synthesis of cathode materials were carried out by mixing stoichiometric amounts of
anhydrous LiN03 (103.4g g), Cu(N03)2.3H20 (67.03 g), Mg(N03).6H20 (5.77 g) and
Co(N03)2.4H20 (349.25 g), then dissolved in 900 ml triple distilled water. The resulting
metal ion solution was stirred continuously at 300 rpm for 180 min at 95 deg C. The above
concentrated solution was transferred to petri dish and microwaved for 45 min. The solution
was irradiated at full rated power (100% microwave power (2450 MHz microwave
frequency) for 35 minutes. During the reaction, the chemical constituents were rapidly heated
and a red glow was appeared inside the china dish throughout the reaction. After the
completion of reaction the product was dried in an air oven for two hours and the resulting
product was mortar ground for 2 hours in air to obtain phase pure cathode material and sub
micron sized particles. The material was mixed with conducting material and binder to made
in to slurry form and was coated over aluminium foil. It was hot pressed and 1 mm pieces
were punched out.
The Example 2 of the present invention may be repeated in a similar manner with transition
metal salts on nitrates, carbonates, oxylates, acetates and other salts of desired metals for
cathode preparation.
EXAMPLE 3 : Assembly of batteries.
Lithium ion coin cells were assembled inside argon filled glove box using the positive and
the negative electrode as prepared by the aforesaid procedures and a polypropylene film
separator sandwiched between these electrodes. The separator was soaked with an electrolytic
solution of 1M LiPF6 dissolved in a solvent EC (ethylene carbonate)/DEC (diethylene
carbonate) in the ratio of 1:1. The coin cells were subjected to charge discharge cycling at
different C rates for 300 cycles. The experiments were repeated for concordant results and
typical results are presented in Figures 4, 5, 6 and 7.
EXAMPLE 4: Test for cycle life of different batteries according to present invention
The batteries of the present invention were tested for the average cycle life and compared
with prior art and prior used batteries. The batteries prepared according to example 3 were
examined for their cycling behavior by charging at 1C and discharging at various C rates for
300 cycles. The results of the batteries of the present invention are presented at Figures 4, 5, 6
and 7. From the figures, it is evident that the batteries of the present have a superior battery
capacity under cycling conditions in a wide range of discharge rates.
Table 4a: Results obtained by test for charge and discharge cycling rate at variable C
rates for 300 cycles as mentioned above in example 4.
The batteries of the present invention were tested for the average cycle life. The results are
tested at Table 4a.
Table 4a: Charge and discharge capacity of the batteries according to present invention
Battery Charge Initial Charge After 300 cycle
Code /Discharge Capacity
rate
SM2 1C/0.1C 313mAh After 50 cycle (312mAh)
SM8 1C/10C 219mAh 195mAh
SM3 1C/5C 240mAh 4mAh
SM4 1C/1C 257mAh 247mAh
EXAMPLE 5: Comparison of charge discharge behavior of the battery of the present
invention with different brands of lithium ion batteries of prior art and prior use for up
to 300 cycles.
The main purpose of the present invention is to improve charge and discharge capacity at
variable C rates of lithium ion batteries according to the present invention. The present test
involves the comparison of prior art and prior use lithium ion batteries, against the battery of
the present invention. The batteries were tested for the average cycle life and average battery
capacity. The batteries prepared according to example 3 were analyzed for their cycling
behavior by charging at C and discharging at various C rates for 300 cycles. The results are
presented at Figures 8, 9, 10 and 1 and are compared with Figures 4, 5, 6 and 7 (being
drawn to the battery of the present invention). From the figures, it is evident that the batteries
of the present invention have a superior battery capacity under cycling conditions in a wide
range of discharge rates. The results are tabulated at Table 5a.
Table 5a: Comparison of charge and discharge capacity of the batteries according to
present invention with prior art and prior use batteries.
0.1C (50 Cycles) 1C(300 Cycles) 5C(300 Cycles) 10C(300 Cycles)
Cell
Retention Average Retention Average Retention Average Retent
Type Average
% Capacity % Capacity % Capacit ion
Capacity
Ah Ah y %
Ah
Ah
V- 0.298 100 0.248 73 0.200 77 0.2 11 65
Type (V6) (V I) (V2) (V8)
0.248 87 0.2 12 67
(V4) (V3)
G- 0.275 100 0.233 86 0.205 76 0.0 10 10
Type (G6) (Gl ) (G8) (G2)
and Both
0.248 100 (G3) Fai led
(G9)
SM- 0.312 100 0.257 96 0.227 89 0.204 9 1
Type (SM2) (SM4) (SM3) (SM8)
V2- 0.235 94 0.222 99 0.200 86 0.203 9 1
Type (V2-2) (V2-4) (V2-3) (V2-8)
INFERENCE: From Table 5a and figures as referred herein above, it may be noted on the
basis of parameters evaluated, SM type batteries, being the batteries of the present invention
shows maximum charge and discharge capacity rate at all variable C rates
Example 6: Comparison of the thermal runaway and short circuit behavior of prior art
prior use batteries with that of the batteries of the present invention.
The thermal runaway and short circuit behavior of prior art prior use batteries were compared
with that of the batteries of the present invention. The results of prior art, prior use batteries
are listed at Figures 12, 13, 14 and 5 and that of the present invention are listed at Figures
16 and 17. From the figures listed herein, it is evident that the batteries of the present
invention exhibit excellent characteristics in thermal runaway and short circuit tests and were
found to be better than prior art and prior use batteries.
Thus above description, examples, tables and figures clearly indicate that the battery
according to present invention has advantageous merit over that of batteries of prior art and
prior use.

We claim:
1. An improved lithium ion battery for electronic devices comprising
a. a cathodic material;
b. an anodic material;
c. an electrolyte;
d. a separator;
e. current collectors;
wherein, the said battery has a charging capacity of 110 to 190 mAh/g;
wherein, the said battery has a potential window of 3 to 4.5 v;
wherein, the said battery has a discharge rate of 10 to 15 times the battery capacity
and is capable of cycling for 300 to 500 cycles.
2. The lithium ion battery as claimed in claim 1, wherein the cathodic material is
selected from the group comprising lithium cobalt oxide, lithium iron phosphate,
lithium manganese cobalt oxide, lithium nickel cobalt Aluminium oxide or mixtures
thereof.
3. The cathodic material as claimed in claim 2, is optionally doped with transition metal
cations selected from the group comprising Ti, Zr, Mn, Ni, Fe, Cu or non transition
metal cations selected from the group comprising Al, Sn, Ga, Mg.
4. The lithium ion battery as claimed in claim 1, wherein the anodic material is selected
from the group comprising graphitic carbon, carbon nanotubes, fullerene and
graphene and mixtures thereof.
5. The anodic material as claimed in claim 4, optionally comprises materials, selected
from the group comprising nickel, aluminum, tin, germanium and lead or mixtures
thereof, in their oxidized or un-oxidized state.
6. The lithium ion battery as claimed in claim 1, wherein the separator material is any
one of polyethylene, polypropylene, fluorinated co-polymers with at least one
hydroxyl group.
7. The lithium ion battery as claimed in claim 1, wherein the electrolytic material is a
liquid, and is selected from an ionic liquid including LiPF6, LiBF4, LiC104, organic
carbonate liquid, a liquid polymer or a gel electrolyte or mixtures thereof or a solid
and is selected from a polymeric material, including Lithium salt in conjunction with
lanthanum, stannum and germanium, zirconium, tantalum and titanium or mixtures
thereof.
8. The lithium ion battery as claimed in claim 1, wherein the collector material is
selected from the group comprising Aluminum or Copper, which further comprises
thin coatings of metal or inter-metallic compounds selected from the group
comprising, iron, nickel, titanium, copper.
9. A process for preparing the lithium ion battery as claimed in claim 1, comprising the
steps of ;
i. preparation of the anodic material;
ii. preparation of the cathodic material;
iii. preparation of the electrolytic material;
iv. preparation of the separator;
v. preparation of the collector;
vi. assembly of components of steps (i) to (v).
10. A lithium ion battery as claimed in claim 1, wherein, the charge management is
controlled by an integrated circuit and the energy management is controlled by a
programmable electronic controller.
11. The lithium ion battery as claimed in claim 1, wherein the charging capacity is in the
range of 110 to 220 mAh/g, preferably, 130 to 200 mAh/g, more preferably, 140 to
190 mAh/g.
12. The lithium ion battery as claimed in claim 1, wherein the potential window is the
range of 3.0 to 4.5 V.
. The lithium ion battery as claimed in claim 1, wherein the battery has a discharge rate
in the range of 0.1 to 15 C, preferably, 1 C to 13C, more preferably 5C to 12 C and
charging rate in the range of 0.1 to 5 C, preferably, 1 to 3 C.
14. The lithium ion battery as claimed in claim 1, wherein the thermal runaway associated
with short circuit is prevented by an electronic circuit.
15. Use of the lithium ion battery as claimed in claim 1 for electronic devices, selected
from the group comprising electronic cigarettes, portable charging packs, vaping
devices, inhalation devices, preferably, electronic cigarettes.