Duan Xudong, Li Jiani, Jia Yikai, Gao Xiang, Wang Lubing, Xu Jun
Department of Automotive Engineering, School of Transportation Science and Engineering, Beihang University, Beijing, 100191, China.
Department of Mechanical Engineering and Engineering Science, The University of North Carolina at Charlotte, Charlotte, NC, 28223, USA.
Adv Sci (Weinh). 2023 Oct;10(29):e2302496. doi: 10.1002/advs.202302496. Epub 2023 Aug 9.
The characteristics of internal short circuits (ISC) play a critical role in determining the thermal runaway behaviors and associated hazards of lithium-ion batteries (LIBs). However, due to safety concerns and limitations in operando characterization at high state-of-charges (SoCs), the fundamental understanding of stress-driven ISCs under high SOC situations (above 30%) is still lacking. In this study, combined post-mortem characterization and multiphysics modeling is employed to clarify the evolution of ISC modes in LIBs with high SOCs. These findings reveal that the triggered ISC mode is SOC-dependent, with the Al current collector (Al)-Anode coating (An) mode dominant in high SOC situations. Experimentally obtained ISC resistance for the specified ISC mode is then assigned to the corresponding ISC region in the established multiphysics model, allowing for accurate coupling of the electromechanical relationship and prediction of mechanical-electrical-thermal responses of the LIB. Finally, a simple yet effective approach is proposed for avoiding the Al-An mode after battery fractures, achieved through surface notches on electrodes. Results discover novel phenomena for ISC in high SOC cells and reveal the underlying mechanisms, highlighting the importance and potential of battery structural design for developing next-generation robust batteries.
内部短路（ISC）的特性在决定锂离子电池（LIB）的热失控行为及相关危险方面起着关键作用。然而，由于安全方面的考虑以及在高充电状态（SoC）下进行原位表征的局限性，对于高SoC情况（高于30%）下应力驱动的ISC的基本理解仍然不足。在本研究中，采用了结合事后表征和多物理场建模的方法来阐明高SoC的LIB中ISC模式的演变。这些发现表明，触发的ISC模式取决于SoC，在高SoC情况下，铝集流体（Al）-负极涂层（An）模式占主导。然后将针对特定ISC模式通过实验获得的ISC电阻分配到所建立的多物理场模型中的相应ISC区域，从而实现机电关系的精确耦合以及对LIB的机电热响应的预测。最后，提出了一种简单而有效的方法，通过在电极上设置表面缺口来避免电池破裂后的Al-An模式。研究结果发现了高SoC电池中ISC的新现象，并揭示了其潜在机制，突出了电池结构设计对于开发下一代坚固型电池的重要性和潜力。
