Lithium ion battery additive, electrolyte and anode slurry

Abstract

The invention belongs to the technical field of lithium ion batteries, and particularly discloses a lithium ion battery additive, electrolyte and anode slurry. The additive comprises one or more bismaleimide compound with a structure in a general formula I or general formula II. The electrolyte comprises electrolyte salt, a non-aqueous solvent and the additive. The anode slurry comprises an anode active material, a conductive agent, an adhesive and the additive. The structure of the additive contains a large number of unshared ion pairs and polar functional groups, the additive has strong interaction force with a metal oxide electrode material and a current collector, dispersity of metal oxide anode particles can be improved in the anode slurry, the bonding power between an electrode material coating and the current collector is remarkably improved, and the cycling performance is improved. The structure of the additive further contains a large number of double bonds, electrochemically oxidative polymerization can be realized under high voltage, a more stable SEI (solid electrolyte interface) film can be formed on the surface of the anode material, and exothermic auxiliary reaction of the anode material and the electrolyte at high temperature and under high voltage is effectively weakened.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an additive, electrolyte and positive electrode slurry for high specific energy lithium ion batteries. Background technique [0002] With the development of the economy and the progress of science and technology, the human demand for energy continues to rise. In view of the increasing scarcity of traditional primary fossil energy such as oil and natural gas and the increasingly serious environmental problems such as air pollution and greenhouse effect caused by large-scale use, the development of clean and renewable energy has become a major strategy for the development of the international community. As an efficient and clean energy storage device that can be recycled, secondary batteries are an important technical approach to comprehensively alleviate energy, resource and environmental problems. Compared with other secondary battery systems such as le...

AI Technical Summary

Problems solved by technology

However, electrode materials with higher discharge specific capacity often have poor processing performance due to smaller primary particles, such as poor adhesion with the current collector and easy de-foiling; lithium-rich manganese-based electrode materials have higher workability The voltage (4.6-4.8V) leads to more severe side reactions between the positive electrode material and the electrolyte, and worse safety performance

It can be seen that only by changing the material itself, the best application performance of the electrode material cannot be achieved. Therefore, other methods need to be further developed to improve the application performance of high specific energy lithium-ion batteries.

[0005] Ternary cathode materials are more and more widely used due to their safety and cost advantages, but their energy density and gram capacity still need to be improved

[0013] The electrode slurry additives mentioned above are mostly branched structure polymers formed by modification of multifunctional compounds. The preparation of additives is relatively cumbersome, and the addition of multifunctional compounds will introduce new impurities into the positive electrode slurry. These impurities It will also affect the electrochemical performance of lithium-ion batteries to varying degrees; such as modifiers cyanamide and melamine, not only introduce cyano impurities, but also because cyanide itself is a highly toxic substance, there are potential safety hazards in the production process, which is not conducive to industrial scale production

[0014] Therefore, still need to develop a kind of dispersibility height, viscosity is low, can improve electrolyte and anode slurry performance, and can improve battery cycle performance and safety performance good high specific energy lithium-ion battery additive, prior art has not yet effectively local solution

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