Specification Title of Invention: Lithium secondary battery with improved high temperature storage characteristics Technical field [One] Cross-reference with related application(s) [2] This application claims the benefit of priority based on Korean Patent Application No. 2018-0011216 filed January 30, 2018 and Korean Patent Application No. 2019-0009128 filed January 24, 2019, and all disclosed in the documents of the relevant Korean patent application. The content is incorporated as part of this specification. [3] [4] Technical field [5] The present invention relates to a lithium secondary battery with improved high temperature storage characteristics. Background [6] Recently, interest in energy storage technology is increasing, and as its application fields are expanded to energy sources of mobile phones, camcorders and notebook PCs, and furthermore, electric vehicles, efforts for research and development of electrochemical devices are increasingly being concreted. [7] In particular, interest in rechargeable secondary batteries is emerging among electrochemical devices, and among them, lithium secondary batteries developed in the early 1990s are in the spotlight for their advantages of high operating voltage and remarkably large energy density. [8] Currently applied lithium secondary batteries are composed of a negative electrode capable of occluding and releasing lithium ions, a positive electrode made of a transition metal oxide containing lithium, and a non-aqueous electrolyte in which a lithium salt is dissolved in a carbonate-based organic solvent. [9] In the lithium secondary battery, lithium ions from the positive electrode are inserted into the negative electrode by charging, and during discharging, lithium ions are repeatedly desorbed while transferring energy to enable charge and discharge. [10] On the other hand, lithium secondary batteries form a film on the anode surface as some of the electrolyte additive components and organic solvents decompose in the 0.5V~3.5V range during initial charging, and lithium ions generated from the anode move to the cathode, In the reaction with the electrolyte to produce compounds such as Li 2 CO 3 , Li 2 O, LiOH. These compounds form a kind of passivation layer on the surface of the negative electrode, which is called a solid electrolyte interface (SEI) film. [11] The SEI film formed at the beginning of charging serves as a protective film to stabilize the battery by suppressing the decomposition of the carbonate-based electrolyte on the surface of the negative electrode. [12] However, the SEI film produced only by the organic solvent and the lithium salt is somewhat insufficient to perform the role as a continuous protective film, so that the charging and discharging of the battery continues to proceed, especially when stored at a high temperature in a fully charged state, increased electrochemical energy. And can be slowly decayed by thermal energy. Due to the collapse of the SEI film, side reactions in which the exposed surface of the negative electrode active material and the electrolyte solution react and decompose continuously occur, resulting in deterioration of battery characteristics, such as a decrease in capacity, a decrease in life, and an increase in resistance. In addition, such side reactions cause the generation of gases such as CO, CO 2 , CH 4 , and C 2 H 6 inside the battery, and such continuous gas generation increases the internal pressure of the lithium secondary battery at high temperatures to expand the battery thickness. Not only does it cause a problem, but it also causes problems in the safety of the secondary battery. [13] [14] (Prior technical literature) Japanese Laid-Open Patent Publication No. 2017-117684 Detailed description of the invention Technical challenge [15] In the present invention, by including a non-aqueous electrolyte capable of forming a solid film on the electrode surface, it is intended to provide a lithium secondary battery capable of securing capacity characteristics even at high temperature storage. Means of solving the task [16] In order to solve the above problem, in one embodiment of the present invention [17] A positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, [18] The positive electrode includes a positive electrode active material represented by Formula 1 below, [19] The non-aqueous electrolyte contains a non-aqueous organic solvent, a first lithium salt, a second lithium salt, lithium bis (fluorosulfonyl) imide, and an additive, [20] At this time, the molar ratio of the first lithium salt: the second lithium salt is 1:0.01 to 1:1, [21] The additive provides a lithium secondary battery that is a mixed additive containing fluorobenzene, tetravinylsilane, and tertiary butylbenzene in a weight ratio of 1:0.05:0.1 to 1:1:1.5. [22] [Formula 1] [23] Li(Ni a Co b Mn c )O 2 [24] In Formula 1, [25] 0.65