Negative electrode slurry for lithium ion batteries

Abstract

Relating to the technical field of lithium ion battery manufacturing, the invention discloses a negative electrode slurry for lithium ion batteries. The negative electrode slurry for lithium ion batteries is prepared from a negative electrode active material, a conductive agent, a negative electrode binder, 20-25 parts of a solvent and other raw materials, wherein the negative electrode active material is spherical graphite, the conductive agent is carbon nanotube, and the solvent is N-methyl pyrrolidone. The binder added in the negative electrode slurry provided by the invention has good binding performance, can bind the negative electrode active material together better and more evenly, and also is suitable for batteries needing higher cycle performance. The negative electrode slurry binder used in the invention can improve the safety performance of the negative electrode slurry, so that assembled lithium ion batteries can automatically stop heat generation reaction at high temperature to ensure the safety of lithium ion batteries during use. The negative electrode slurry provided by the invention has more excellent cycle performance, the prepared lithium ion batteries have higher capacity, and also has the characteristic of automatic cut-off of heat generation reaction at high temperature.

Description

technical field [0001] The invention relates to the technical field of manufacturing lithium ion batteries, in particular to a negative electrode slurry for lithium ion batteries. Background technique [0002] In recent years, the rapid development of portable electronic products, electric vehicles, energy storage power stations and other fields has put forward higher requirements for energy storage technology. Lithium-ion batteries are the first choice in these fields due to their high energy density, and their energy density is getting higher. As the energy density of lithium-ion batteries is getting higher and higher, the safety problems it faces are becoming more and more severe, which has severely limited the terminal use of high-energy-density lithium-ion batteries. [0003] The safety problem of lithium-ion batteries is mainly due to the thermal runaway of batteries. Due to the abnormal heat generation reaction inside the battery, the internal temperature of the bat...

AI Technical Summary

Problems solved by technology

However, since the ceramic-coated diaphragm can only improve the thermal stability of the diaphragm, it cannot block the side reaction of heat generation, so its improvement effect is limited.

At present, it can only solve the safety problem of batteries with an energy density of no more than 200wh / kg; method 2 can partially contain the thermal runaway reaction of the battery, but because the electrodes of lithium-ion batteries are usually porous electrodes, the electrolyte is filled in the abundant electrode gaps; although The conduction of lithium ions between the positive and negative electrodes is blocked, but the reaction between the active material inside the electrode and the electrolyte is still going on, which will further lead to heat accumulation and trigger a thermal runaway reaction. Method 2 cannot be applied to high-energy and high-power lithium Ion battery system