The present invention relates to a process for recovery and recycling of manganese dioxide from waste lithium ion batteries. More particularly, it relates to recycling of lithium ion-based batteries that has been discarded and not in use to extract manganese dioxide from them for its reuse for various industrial processes.
BACKGROUND OF THE INVENTION
Lithium-ion batteries (LiBs) are being used from several years for different applications including consumer electronics due to high energy density, long life and discharging capability. LiBs comprise a cathode, an anode and an electrolyte which includes lithium as transition metal oxide.
Nowadays, LiBs are commonly used for automotive propulsion as these batteries provides several years of honest service and lasts for around 10 years while using under normal driving conditions.
The environmental issues of used LiBs are a matter of concern for the general public. When the functional materials are recovered from the exhausted batteries the need for raw materials to be extracted from the ground is reduced. Also, the environmental issues caused due to mining and processing of ores are avoided as LiBs are recycled.
WO2017/118955 relates to a process and method of recovering metals of value from used LiBs for recovering cobalt, lithium, manganese along with other metals of value from used LiBs rich in manganese content.
Chen et al.f 2016 relates to a process combined with reductive leaching and selective precipitation to recover valuable metals from waste cathode materials of spent LiBs including manganese oxides (Chen et al., J. Clean. Prod., 2016 (112), 3562-3570).

CN107017443B relates to the processing method of waste and old lithium ion battery, more particularly to one kind are comprehensive from waste and old lithium ion battery to recycle the smelting process of the valuable elements such as lithium, nickel, cobalt, manganese, copper, or aluminium.
However, methods for recycling of LiBs heretofore known suffer from a number of disadvantages including that the existing methods have low values for recovery of the LiBs salts and utilization of by-products, techniques for recycling Li-ions are limited, the recycled LiBs are too heavy, the transportation and the disassembly are inconvenient, the next recycling is inconvenient, and the inside of the recycled LiBs generates moisture.
Accordingly, there is a need for an approach that resolves problems of state of art to provide a simple process for recovery and recycling of salts from Lithium-ion based batteries. For extraction of manganese dioxide salt from LiBs a reactor, filtration techniques, potential hydrogen balances, evaporation techniques and crystallizers need to be optimised during the hydrometallurgical process to provide a method which is convenient, easy to process and with lucid steps to follow with proper safety.
OBJECT OF THE INVENTION
The main object of the present invention is to provide a process for recovery and recycling of manganese dioxide from waste lithium ion batteries (LiBs) for its reuse for various industrial processes.
Another object of the present invention is to provide a process for extraction of manganese dioxide from waste LiBs comprising the steps of shredding of waste batteries to crushed lithium ion battery in pieces/ leaf, and recovery of manganese dioxide by hydrometallurgy process.
Still another object of the present invention is to provide a process for extraction of manganese dioxide from waste LiBs by optimising filtration

techniques, potential hydrogen balances, a reactor, evaporation techniques, and crystallizers during the hydrometallurgical process to provide a method which is convenient, easy to process and with lucid steps to follow with proper safety.
SUMMARY OF THE INVENTION
The present invention relates to recycling of LiBs that has been discarded and not in use to extract manganese dioxide from LiBs for its reuse for various industrial processes.
In a preferred embodiment, the present invention provides a process for recovery of manganese dioxide from waste lithium ion batteries comprising the steps of shredding the batteries to crushed lithium ion battery in pieces/ leaf which is further processed by a hydrometallurgical process to obtain manganese dioxide salt.
In another preferred embodiment, the present invention provides a process for recovery and recycling of manganese dioxide from waste lithium ion batteries comprising steps of: a) crushing said waste lithium ion batteries into pieces/ leafs and processing said pieces with chemicals in a reactor unit at predefined temperature and time to provide a slurry of reaction mixture; b) filtering said slurry of reaction mixture obtained in said step a) to procure a filtrate; c) feeding said filtrate obtained in said step b) to reactor wherein said solution is adjusted to a desired pH through sodium hydroxide w/v; d) filtering said pH adjusted solution obtained in said step c) to receive said filtrate; e) feeding said cake obtained in said step d) to reactor for processing with potassium permanganate to form a solution; f) filtering said solution obtained in said step e) to remove manganese dioxide in form of cake.
The present invention provides a method for recovery of manganese dioxide and recycling of waste lithium ion batteries for its reuse in several industrial

processes. For the extraction of manganese dioxide from lithium ion batteries a reactor, filtration techniques, potential hydrogen balances, evaporation techniques, and crystallizers are optimised during the hydrometallurgical process to provide a method which is convenient, easy to process and with lucid steps to follow with proper safety.
The above objects and advantages of the present invention will become apparent from the hereinafter set forth brief description of the drawings, detailed description of the invention, and claims appended herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of a process for recovery of manganese dioxide salt from waste lithium ion batteries of the present invention may be obtained by reference to the following drawings:
Figure 1 depicts a flowchart of extraction of manganese dioxide salt from waste lithium ion batteries (LiBs) in accordance with an embodiment of the invention.
Figure 2 depicts an extracted manganese dioxide salt obtained from waste lithium ion batteries (LiBs) in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully hereinafter. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough, and will fully convey the scope of the invention to those skilled in the art.

The present invention relates to recycling of lithium ion batteries that has been discarded and not in use to extract manganese dioxide salt from them for its reuse for various industrial processes.
In a preferred embodiment, the present invention provides a process for recovery of manganese dioxide salt from waste lithium ion batteries comprising the steps of crushing the batteries to crushed lithium ion battery pieces/ leaf which is further processed by hydrometaUurgical process to obtain manganese dioxide salt.
Referring to Figure 1, a flowchart of extraction of manganese dioxide salt from waste lithium ion batteries (LiBs) is illustrated. The present invention provides a process for recovery of manganese dioxide salt from waste lithium ion batteries comprising the steps of:
a) crushing said waste lithium ion batteries in to pieces which is processed with chemicals including but not limited to sulphuric acid, hydrogen peroxide and demineralised water in reactor at 90°C for four hours in a reactor unit to provide a slurry of reaction mixture;
b) filtering said slurry of reaction mixture obtained in the step a) to obtain a filtrate and subjecting said filtrate for further processing;
c) feeding said filtrate obtained in the step b) to reactor wherein pH of the solution is adjusted to 3.5 using sodium hydroxide w/v;
d) filtering said pH adjusted solution obtained in said step c) to receive a filtrate;
e) feeding said filtrate obtained in the step d) to reactor for further processing with potassium permanganate to form a solution; and
f) filtering the solution obtained in the step e) to remove manganese dioxide in form of cake with the recovery of around 3.0 kg - 3.5 kg

(37.5% to 43.75%) of manganese dioxide from 8 kg powder of lithium ion battery.
2MnS04+ 2KMn04 + H20 ► 4Mn02 + K2S04 + H2S04
EXAMPLE 1 Experimentation Analysis
The present invention provides a process for recovery of manganese dioxide salt from waste lithium ion batteries (LiBs) from 8 kg powder of lithium ion battery in which 2.344% of manganese is present, comprises steps of:
a) crushing said waste lithium ion batteries into pieces which is processed with chemicals including but not limited to sulphuric acid ranging between 3 to 4 litres, hydrogen peroxide ranging between 5.5 to 6.5 litres and demineralised water ranging between 60 to 65 litres in reactor at 90°C for four hours in a reactor unit to provide a slurry of reaction mixture;
b) filtering said slurry of reaction mixture obtained in said step a) to obtain a filtrate and subjecting said filtrate for further processing;
c) feeding said filtrate obtained in the step b) to reactor wherein pH of the solution is adjusted ranging between 3 to 4 using sodium hydroxide w/v ranging between 10 to 20 ml/100 ml of filtered solution;
d) filtering said pH adjusted solution obtained in said step c) to receive said filtrate;
e) feeding said filtrate obtained in said step d) to reactor for further processing with potassium permanganate ranging between 250 to 300 gm to form a solution;

f) filtering said solution obtained in said step e) to remove manganese dioxide in form of cake with the recovery of around 0.3kg-0.35kg of manganese dioxide from 8 kg powder of lithium ion battery.
2MnS04+ 2KMn04 + H20 ► 4Mn02 + K2S04 + H2S04
Referring to Figure 2, an extracted manganese dioxide salt obtained from waste lithium ion batteries (LiBs) is depicted. The manganese dioxide salt so obtained is blackish/brown solid after the hydrometallurgical process as disclosed in an embodiment.
Therefore, the present invention provides a method for recovery of manganese dioxide salt and recycling of waste lithium ion batteries for its reuse in several industrial processes. For the extraction of manganese dioxide salt from LiBs a reactor, filtration techniques, potential hydrogen balances, evaporation techniques, and crystallizers are optimised during a hydrometallurgical process to provide a method which is convenient, easy to process and with lucid steps to follow with proper safety.
Many modifications and other embodiments of the invention set forth herein will readily occur to one skilled in the art to which the invention pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

CLAIMS
We claim:

1. A process for recovery and recyding of manganese dioxide from waste
lithium ion batteries comprising steps of:
a) crushing the waste lithium ion batteries into pieces and processing said pieces with chemicals in a reactor unit at predefined temperature and time to provide a slurry of reaction mixture;
b) filtering said slurry of reaction mixture obtained in said step a) to procure a filtrate;
c) feeding said filtrate obtained in said step b) to reactor wherein said solution is adjusted to a desired pH through sodium hydroxide w/v;
d) filtering said pH adjusted solution obtained in said step c) to receive said filtrate;
e) feeding said filtrate obtained in said step d) to reactor for processing with potassium permanganate to form a solution;
f) filtering said solution obtained in said step e) to remove manganese dioxide in form of cake;
wherein:
said recovery of manganese dioxide is around 0.3 to 3.5 kg of lithium carbonate from 8 kg powder of lithium ion battery having purity of 98.9%.
2. The process for recovery and recyding of manganese dioxide from waste
lithium ion batteries as daimed in claim 1, wherein said chemicals

including but not limited to sulphuric acid ranging between 3 to 4 litres, hydrogen peroxide ranging between 5.5 to 6.5 litres and demineralised water ranging between 60 to 65 litres at 90°C for four hours in a reactor unit.
3. The process for recovery and recycling of manganese dioxide from waste lithium ion batteries as claimed in claim 1, wherein said pH of said solution is adjusted ranging between 3 to 4 in said step c) through sodium hydroxide w/v ranging between 10 to 20 ml/100 ml of filtered solution.
4. The process for recovery and recycling of manganese dioxide from waste lithium ion batteries as claimed in claim 1, wherein said potassium permanganate is ranging between 250 to 300 gm.
5. The process for recovery and recycling of manganese dioxide from waste lithium ion batteries as claimed in claim 1, wherein said reactor is a batch reactor with temperature ranging between 85 to 95°C and pressure ranging between 1 to 2 bar.