Electrolysis liquid for lithium manganate battery

Abstract

The invention discloses electrolyte solution of a manganic acid lithium battery. The electrolyte solution comprises lithium salt, non-aqueous organic solvent, film-forming additive and stabilizing additive, namely seven-methyl two-silazane. Because the stabilizing additive, seven-methyl two-silazane is added into the electrolyte solution, the acidity of the electrolyte solution can be controlled. The cycle life and the high temperature storage performance of a lithium ion battery can be improved by using the electrolyte solution to prepare a battery.

Description

technical field

[0001] The invention relates to an electrolyte solution for a lithium ion battery, in particular to an electrolyte solution for a lithium manganate battery. Background technique

[0002] There are four types of secondary batteries commonly used at present: lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries and lithium-ion batteries. Lithium-ion batteries have the characteristics of high working voltage, small size, light weight, high specific energy, no memory effect, small self-discharge, long cycle life, and no pollution to the environment. The power supply of portable computers, cameras, etc. has gradually replaced traditional batteries in the fields of aviation, aerospace, navigation, artificial satellites, small medical instruments and military communication equipment. It is an ideal energy source for the development of the 21st century.

[0003] Commercial lithium-ion batteries were first introduced by Sony in the 1990s. Lit...

Examples

Embodiment 1

[0034] LiPF as lithium salt 6 The obtained solution dissolved in the mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) / propylene carbonate (PC) (mass ratio is 30 / 60 / 10), wherein LiPF 6 The concentration is 1M. Then, vinylene carbonate (VC) was added into the solution by 2% of the total weight of the electrolyte, and heptamethyldisilazane was added by 0.1% of the total weight of the electrolyte to obtain the desired electrolyte. Denote it as sample B.

[0035] Add 1 drop of distilled water to sample A and sample B respectively, test the water content in the electrolyte by the coulometric method, and test the acidity in the electrolyte by acid-base titration.

[0036] H of sample A and sample B before and after being placed at room temperature for one week 2 The results of O and HF content are as follows:

[0037]

[0038] The concentration of free acid (HF) in the electrolyte with heptamethyldisilazane was significantly lower.

[0039] figure 1 The ...

Embodiment 2

[0042] LiPF as lithium salt 6 The obtained solution dissolved in the mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) / diethyl carbonate (DEC) / propylene carbonate (PC) (mass ratio is 30 / 10 / 50 / 10) , where LiPF 6 The concentration is 1M. Then, vinylene carbonate (VC) was added into the solution by 2% of the total weight of the electrolyte, and heptamethyldisilazane was added by 0.5% of the total weight of the electrolyte to obtain the desired electrolyte.

Embodiment 3

[0044] LiPF as lithium salt 6 The obtained solution dissolved in the mixed solvent of ethylene carbonate (EC) / ethyl formate (EF) / dimethyl carbonate (DMC) (mass ratio is 30 / 20 / 50), wherein LiPF 6 The concentration is 1.4M. Then add 1,3-propiolactone sulfonate (1,3-PS) to the solution by 3% of the total weight of the electrolyte, and add heptamethyldisilazane by 1% of the total weight of the electrolyte to obtain Get the desired electrolyte.

technical field

[0001] The invention relates to an electrolyte solution for a lithium ion battery, in particular to an electrolyte solution for a lithium manganate battery. Background technique

[0002] There are four types of secondary batteries commonly used at present: lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries and lithium-ion batteries. Lithium-ion batteries have the characteristics of high working voltage, small size, light weight, high specific energy, no memory effect, small self-discharge, long cycle life, and no pollution to the environment. The power supply of portable computers, cameras, etc. has gradually replaced traditional batteries in the fields of aviation, aerospace, navigation, artificial satellites, small medical instruments and military communication equipment. It is an ideal energy source for the development of the 21st century.

[0003] Commercial lithium-ion batteries were first introduced by Sony in the 1990s. Lit...

Examples

Embodiment 1

[0034] LiPF as lithium salt 6 The obtained solution dissolved in the mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) / propylene carbonate (PC) (mass ratio is 30 / 60 / 10), wherein LiPF 6 The concentration is 1M. Then, vinylene carbonate (VC) was added into the solution by 2% of the total weight of the electrolyte, and heptamethyldisilazane was added by 0.1% of the total weight of the electrolyte to obtain the desired electrolyte. Denote it as sample B.

[0035] Add 1 drop of distilled water to sample A and sample B respectively, test the water content in the electrolyte by the coulometric method, and test the acidity in the electrolyte by acid-base titration.

[0036] H of sample A and sample B before and after being placed at room temperature for one week 2 The results of O and HF content are as follows:

[0037]

[0038] The concentration of free acid (HF) in the electrolyte with heptamethyldisilazane was significantly lower.

[0039] figure 1 The ...

Embodiment 2

[0042] LiPF as lithium salt 6 The obtained solution dissolved in the mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) / diethyl carbonate (DEC) / propylene carbonate (PC) (mass ratio is 30 / 10 / 50 / 10) , where LiPF 6 The concentration is 1M. Then, vinylene carbonate (VC) was added into the solution by 2% of the total weight of the electrolyte, and heptamethyldisilazane was added by 0.5% of the total weight of the electrolyte to obtain the desired electrolyte.

Embodiment 3

[0044] LiPF as lithium salt 6 The obtained solution dissolved in the mixed solvent of ethylene carbonate (EC) / ethyl formate (EF) / dimethyl carbonate (DMC) (mass ratio is 30 / 20 / 50), wherein LiPF 6 The concentration is 1.4M. Then add 1,3-propiolactone sulfonate (1,3-PS) to the solution by 3% of the total weight of the electrolyte, and add heptamethyldisilazane by 1% of the total weight of the electrolyte to obtain Get the desired electrolyte.

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