High-energy-density lithium ion battery

Abstract

The invention relates to a high-energy density lithium ion battery. A positive electrode including one or more of the following components: LiCoO2, Li(NixMnyCo1-x-y)O2 (x is greater than or equal to 0and less than or equal to 1, y is greater than or equal to 0 and less than or equal to 1), Li(NixCoyAl1-x-y)O2 (x is greater than or equal to 0 and less than or equal to 1, y is greater than or equalto 0 and less than or equal to 1), Li2MnO4, LiNi0.5Mn0.5O2, LiNi0.5Mn1.5O4, LiMPO4, and aLi2MnO3.(1-a)Li(NixMnyCo<1-x-y>)O2 (x is greater than or equal to 0 and less than or equal to 1, and y is greater than or equal to 0 and less than or equal to 1). The negative electrode comprises surface-modified silicon particles, a carbon conductive agent capable of forming a conductive network, an organicpolymer binder with high tensile strength and high elastic deformation characteristics, and a current collector substrate beneficial to electron conduction. The energy density of the battery can be improved, the rate capability and the low-temperature performance of the battery are improved, and the safety performance is better.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a high energy density lithium ion battery. Background technique [0002] In recent years, with the gradual consumption of traditional fossil energy and the increasingly serious problem of global warming, people are increasingly aware of the importance of new energy in the future society. In all new energy systems, solar energy, wind energy, water energy, nuclear energy, etc. do not have convenient mobility; and lithium-ion batteries, as a portable form of energy storage, have their specific irreplaceability in practical applications So it is widely used. [0003] In 2017, before China’s National Development and Reform Commission stated that it would stop selling domestic traditional fuel vehicles in 2030, many countries had already announced a timetable for a complete ban on the sale of fuel vehicles: Britain and France set the target time for a complete ban on the sale of t...

AI Technical Summary

Problems solved by technology

Therefore, the consequence is that silicon has a serious volume effect in the process of completely inserting and removing lithium, and the volume change rate is about 400%. Most of them lose their electrochemical activity; in addition, due to the volume effect during charge and discharge, the solid electrolyte interface (SEI) protective layer formed on the surface of the silicon material is continuously broken and the fresh silicon surface is repeatedly exposed to the electrolyte, so it will Continuous consumption of electrolyte to form a new SEI film will adversely affect the cycle performance of the battery

Although people think of many kinds of composite structures using silicon and carbon materials or graphite materials, they still cannot solve the above problems well.

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