Experimental study on the dynamic behavior of prismatic lithium-ion battery upon repeated impact

The daily use of electric vehicles may cause mechanical loading on their batteries, either from one-time impact or repeated/accumulated impact from vibrations, curbstone impact, or minor contacts/scratches. Such repeated impact may ultimately lead to short-circuit failure of the batteries. Open literature comprehensively discusses the one-time impact, but a gap remains regarding battery safety behaviors in repeated impact cases. Therefore, in this study, the dynamic behavior of prismatic lithium-ion battery (PLIB) under repeated impact is experimentally in-vestigated for the first time. The relationships between battery failure of short circuit with impact velocity, impact energy and impact times are revealed. The quantitative relationship between battery failure and indentation depth is constructed. Results show that the increase of impact velocity and energy significantly decreases the number of short-circuit impact. For the prismatic lithium-ion battery studied in this work, under the drop-weight impact test with 34.6 kg weight and 25 mm diameter of the hemispherical impact indenter, once the impact velocity reaches more than 1.75 and 4.0 m/s, the soft and hard short circuits are triggered, respectively. When the impact speed is less than the corresponding velocity, the battery failure of soft and hard short circuits can occur only after multiple impacts. Results provide new insights for understanding battery failure behaviors upon repeated impact and important guidance for battery design.