The increasing demand for energy storage continues to require batteries to work under various extreme conditions. As a new generation of energy storage technology, lithium ion batteries have been widely researched and applied, but they can only work in room temperature environments.
This is important because high or low temperatures will cause battery performance to deteriorate. Especially under high temperature conditions, a large amount of heat will float inside, causing explosions and other safety accidents.
In view of this, pulickel M. Ajayan of RiceUniversity and others elaborated the research progress of lithium-ion batteries under extreme temperature conditions (<20℃ or >60℃) in recent years from the perspective of materials of lithium-ion batteries.
1. Cathode material
The positive electrode is the transit center of lithium ions and electrons, and it is easy to undergo phase change. On the other hand, in the case of deep charging, side reactions at the electrode-electrolyte interface tend to make the electrode structure unstable.
2. Negative electrode material
The work of the negative electrode material often depends on the effective heterostructure passivation layer. The increase in temperature will destroy the passivation structure and cause side reactions; while the decrease in temperature will reduce the permeability of lithium ions.
Under low temperature conditions, the electrolyte viscosity increases, hindering ion migration and electrode wettability, reducing the ratio performance; moreover, the reduced conductivity will cause lithium ion consumption around the electrode. Under high temperature conditions, electrolytes are prone to chemical changes and react with charged electrodes.
4. Other materials
In addition to positive electrode materials, negative electrode materials, and electrolyte materials, there are some auxiliary materials in lithium-ion batteries, such as separators, binders, and current collectors. Although these materials have little electrochemical activity and are rarely studied, they are also important factors for ensuring the normal operation of batteries under extreme conditions.