Composite particle for battery, battery separator, and lithium ion battery

Abstract

The invention belongs to the field of batteries, and particularly relates to a composite particle for a battery, a battery diaphragm and a lithium ion battery. The composite particle for the battery comprises a phase change particle and an inorganic compound coating layer coating the surface of the phase change particle, wherein the phase change particles are paraffin, crystalline hydrated salt ormolten salt; and the inorganic compound coating layer is silicon dioxide, attapulgite, kaolinite, montmorillonite, hydrotalcite, vermiculite, sepiolite, mica, illite, diatomite, titanium dioxide, zinc oxide, aluminum oxide or nanocellulose. The composite particle for the battery provided by the invention can effectively control the internal temperature of the lithium ion battery, reduce the internal temperature fluctuation of the lithium ion battery during charging and discharging, absorb part of heat during thermal runaway, reduce the heat release amount of the battery to a certain extent, ensure the safety of the lithium ion battery, and does not affect the electrochemical performance of the battery.

Description

technical field [0001] The invention belongs to the field of batteries, and in particular relates to a battery composite particle, a battery diaphragm and a lithium ion battery. Background technique [0002] As the energy density of lithium-ion batteries gradually increases, its safety has become a bottleneck that limits its large-scale application. When the lithium-ion battery is under abuse conditions (such as mechanical abuse, thermal abuse, etc.), internal short circuits are prone to occur, causing the battery to go out of control. The electric energy stored in the battery will be released in the form of internal energy in a short period of time, causing the internal temperature of the battery to rise sharply, causing thermal runaway of the battery, triggering fire and explosion. In addition, during the operation of the battery, it is inevitable to often encounter behaviors such as overheating (such as charging and discharging at high power, short-term high-temperature ...

AI Technical Summary

Problems solved by technology

[0003] For controlling the temperature of the battery, the existing technical solutions include adding a cooling system outside the battery cell, such as phase change materials, circulating water cooling, air cooling, etc., but these can only regulate the temperature outside the battery, and cannot go deep into the inside

However, the battery is a material with poor thermal conductivity. The external and internal heat conduction resistance of the battery is large, and the internal and external temperature difference will be large.

Therefore, the effect of external temperature control is not good in practical applications

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