Scientists propose a new concept to address the issue of lithium-ion batteries exploding due to overheating

With the popularity of mobile phones, tablets, and electric vehicles, lithium-ion batteries are playing an increasingly important role in people's lives. Battery safety has also become an issue that cannot be ignored. How to improve the safety of lithium-ion batteries and reduce the risk of battery overheating and explosion has become an urgent issue for scientists.

Recently, Matthew Gonzalez, a researcher at the University of California, San Diego, proposed a "spillway" concept to deal with the problem of lithium-ion batteries exploding due to overheating.

The researchers first started with the "lithium dendrite problem".

We all know that a lithium-ion battery is mainly composed of two electrodes, an electrolyte and a separator. The ions start from the lithium cathode, pass through the electrolyte and the separator, and finally reach the graphite anode.

The uncontrolled growth of lithium dendrites can quickly reduce the performance of the battery, shorten the service life of the battery, and even pierce the separator between the electrodes, causing safety problems such as battery short circuit.

To this end, the researchers first attached conductive carbon nanotubes to the separator. When dendrites formed and pierced the separator, electrons would concentrate on the carbon nanotubes and then slowly "flow out" from the battery. This method is like the "spillway" of the reservoir. When the water level in the reservoir exceeds the safe limit, the water will flow downstream from the "spillway" to prevent the dam from being destroyed.

Matthew Gonzalez said: "The new separator slowly drains excess charge, and at the same time prevents electrons from 'spilling' to the cathode side. When it intercepts lithium dendrites, the battery starts to self-discharge, so when the battery is short-circuited There won't be enough energy to explode."

During the detection, the researchers found that the lithium-ion battery equipped with a new separator gradually degrades within 20 to 30 times of charging and discharging, which can provide an early warning; while using a traditional separator, the battery may suddenly break down in a certain cycle , and is completely unpredictable.

At present, there is still a lot of work to be done before the practical use of lithium-ion batteries equipped with "spillways", but the occurrence of a large number of lithium-ion battery safety problems proves the necessity of developing such batteries.