Molecular Engineering of Flame Retardant Material for Safe Lithium‐Based Battery

Lithium-based batteries are widely used in the field of energy storage and conversion system but requires urgent improvement in battery safety. The main reason for the safety risk is the organic electrolytes combustion triggered by the thermal runaway (TR) of the battery and may lead to explosion hazards. Adding flame retardant (FR) to the organic electrolyte is an effective means to solve the safety problem. This paper first discusses the mechanism of organics combustion reaction and analyzes the fire triangle of the combustion reaction including heat (temperature), fuel (organics) and O₂. On this basis, the effect of different kinds of FR at molecular level on inhibiting temperature rise, reducing the electrolyte flammability, and inhibiting the contact between O₂ and organics are discussed, which are used to improve battery safety. Furthermore, the future perspective for the strategies to enhance the safety of lithium batteries is proposed.