Issue 11/2014 - Composite gel separators improve lithium battery safety

Composite gel separator improves the safety of lithium batteries

Recently, the power lithium battery engineering laboratory of Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences designed and prepared a cross-linked composite gel separator based on polyimide non-woven fabric
.
These separators combine the dual advantages
of nonwoven separators and gel polymer electrolytes.
The diaphragm is simple to prepare and easy to industrialize
.

Among them, the non-woven material used as the bottom mold gives the separator excellent thermal dimensional stability, which can effectively prevent the short-circuit explosion accident caused by the melting and shrinkage of the separator in the heating state
.
The cross-linked polyether components inside the diaphragm make the composite diaphragm stable for long-term use, and a gel polymer electrolyte can be formed after being swelled by the electrolyte
.
This design can enhance the stability of the electrolyte inside the diaphragm, overcome the problem of serious leakage when using non-woven diaphragm alone, and further enhance the safety of
the battery during use.
In addition, these separators also exhibit better electrochemical performance
than commercial PP separators.

Lithium batteries as recognized ideal energy storage components have been highly concerned
.
However, in recent years, a series of lithium battery electric vehicle fire accidents show that safety has become the primary bottleneck
restricting the development of power lithium batteries for electric vehicles.
In the structure of lithium batteries, the separator is one of the key inner components, which is made of plastic film to isolate the positive and negative electrodes of the battery to prevent short circuits
.
Therefore, the separator has an important relationship with
battery safety.
(Gong Qingmin)