Analysis of Internal Short Circuit in Lithium ion Batteries

Analysis of Internal Short Circuit in Lithium ion Batteries
The factors that cause internal short circuits in batteries can generally be divided into two categories: battery materials and processes, and battery design and usage. The methods for suppressing and preventing internal short circuits from the above two aspects are summarized as follows:
4.1 In terms of battery materials and processes, improvements are mainly made to separator materials and electrolyte materials, positive and negative electrode coatings, and production processes to reduce production defects.
By using ceramic separators with high temperature resistance and low self discharge rate, as well as flame-retardant electrolytes or ionic liquid electrolytes, dendrite growth can be effectively suppressed and the risk of internal short circuits can be reduced. By coating low conductivity coatings or positive temperature coefficient materials on the current collector or positive and negative electrodes of battery cells, the internal short-circuit current and heat generation capacity can be effectively reduced during internal short circuits, thereby reducing the probability of thermal runaway of the battery. Optimize the production process and impurity removal process of battery cells, separators, and other materials, effectively filter out metal impurities, prevent irreversible side reactions between metal impurities and electrolyte, and reduce the risk of metal particles piercing the separator and causing internal short circuits. In addition, using advanced detection technology to check the internal structural integrity, processing accuracy, and electrode alignment of the battery can also avoid potential internal short circuit risks.
4.2 In terms of battery design and usage, in terms of battery software design, reasonable battery warning and battery safety control strategies are set up through BMS to achieve real-time monitoring of battery cell status, timely detection of internal short circuit battery cell location, and timely elimination of safety hazards. By designing redundancy and balance in battery cell charging and discharging, the risk of internal short circuit caused by high battery load is reduced.