Li Yajie, Sha Liting, Lv Peili, Qiu Na, Zhao Wei, Chen Bin, Hu Pu, Zhang Geng
School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China.
Tencent Inc., Shanghai 200233, China.
Materials (Basel). 2022 Nov 9;15(22):7912. doi: 10.3390/ma15227912.
Li dendrite growth, which causes potential internal short circuit and reduces battery cycle life, is the main hazard to lithium metal batteries. Separators have the potential to suppress dendrite growth by regulating Li distribution without increasing battery weight significantly. However, the underlying mechanism is still not fully understood. In this paper, we apply an electrochemical phase-field model to investigate the influences of separator thickness and surface coating on dendrite growth. It is found that dendrite growth under thicker separators is relatively uniform and the average dendrite length is shorter since the ion concentration within thicker separators is more uniform. Moreover, compared to single layer separators, the electrodeposition morphology under particle-coated separators is smoother since the particles can effectively regulate Li ionic flux and homogenize Li deposition. This study provides significant guidance for designing separators that inhibit dendrites effectively.
锂枝晶生长是锂金属电池的主要危害，它会导致潜在的内部短路并缩短电池循环寿命。隔膜有潜力通过调节锂分布来抑制枝晶生长，而不会显著增加电池重量。然而，其潜在机制仍未被完全理解。在本文中，我们应用电化学相场模型来研究隔膜厚度和表面涂层对枝晶生长的影响。研究发现，较厚隔膜下的枝晶生长相对均匀，且平均枝晶长度较短，因为较厚隔膜内的离子浓度更均匀。此外，与单层隔膜相比，颗粒涂层隔膜下的电沉积形态更平滑，因为颗粒可以有效调节锂离子通量并使锂沉积均匀化。该研究为有效抑制枝晶的隔膜设计提供了重要指导。
