High-security prismatic battery with cover filled agent

Abstract

Thermal runaway has become the primary technical barrier to the further application of lithium-ion batteries. A novel cover is proposed to address the safety issue of a prismatic battery. Battery safety can be enhanced by placing a pharmaceutical bin at the safety valve port, with fusible alloy pieces controlling the agent release time. Experiments are conducted to compare the effect of different agents and the placement of the agents. Results indicate that placing agents at the safety valve port could significantly prolong the thermal runaway propagation time from the front to the rear surface. The optimal effect can be achieved by the NH4H2PO4 outside the battery, which extends the propagation time by 160 times compared with the initial battery design. Most agents could effectively decrease the maximum temperature of the safety valve port, the C14H4Br10 + Sb2O3 outside the battery, which can reduce by 22.4 % at most. Besides, it could reduce the total substantial amount of the gas mixture and the reductive gas during the TR, and the highest reduction of the C14H4Br10 outside the battery is 10.51 % and 15.13 %, respectively. The effect of the outside agent is better than the inside. To comprehensively compare the efficacy of different agents affecting gas mixtures, a map diagram for the agent selection is proposed. It provides a new perspective for the safety prismatic battery design.