Lithium Deposition Behavior of Reconstituted Two-Dimensional Zeolite Y Separators

en This link goes to a English section zh This link goes to a Chinese section During the operation of lithium-ion batteries, uncontrollable lithium dendrite growth often occurs, resulting in internal short circuits and a significant reduction in cycle life, which poses a major obstacle to their practical application. Modification of the separator has emerged as one of the key strategies to suppress lithium dendrite formation. In this study, we modify the surface of a commercial polypropylene (PP) separator using two-dimensional zeolite Y (2D-Y) for lithium-ion batteries. The uniform pores of the zeolite Y provide an effective platform for the homogeneous distribution of lithium ions. The results show that the 2D-Y coating can mitigate the growth of lithium dendrites, thus improving the cell performance. The capacity retention of the 2D-Y-PP cell reaches 77.14% after 1000 cycles at 2C, which is significantly better than the capacity retention of the bare PP cell (less than 25%). At a current density of 0.1 mA cm −2 , the lithium deposition overpotential of the 2D-Y-PP lithium symmetric cell is reduced by 56% compared to the bare PP cell, and the symmetric cell cycle life exceeds 2000 h. Furthermore, the homogenization of lithium deposition is clearly evidenced after 200 cycles. This study demonstrates that the sieving effect of inorganic zeolite coatings modulates lithium deposition kinetics, offering a novel research idea for designing high-safety lithium metal batteries. 摘要 en This link goes to a English section zh This link goes to a Chinese section 锂离子电池运行过程中,常出现不可控的锂枝晶生长现象,导致电池内部短路并显著缩短循环寿命,阻碍了电池的实际应用。改性隔膜已成为抑制锂枝晶形成的关键策略之一。本研究采用二维沸石Y对商用聚丙烯(PP)隔膜表面进行改性,用于锂离子电池。沸石Y均匀的孔道结构为锂离子的均匀分布提供了有效平台。实验结果表明,二维沸石Y涂层能有效抑制锂枝晶生长,从而提升电池性能。在2C倍率下,2D-Y-PP电池经1000次循环后容量保持率达77.14%,显著优于PP基电池(低于25%)。在0.1 mA/cm 2 电流密度下,2D-Y-PP对称电池的锂析出过电位较PP降低56%,且对称电池循环寿命超过2000小时。此外,经过200次循环后,锂沉积的均匀性得到显著提升。本研究证实无机沸石涂层的筛分效应可调控锂沉积动力学,为设计高安全性锂金属电池提供了创新思路。