Sulfur defect engineering controls Li2S crystal orientation towards dendrite-free lithium metal batteries
Jin‐Xia Lin, Peng Dai, Shengnan Hu, Shiyuan Zhou, Gyeong‐Su Park, Chenguang Shi, Jun-Fei Shen, Yuxiang Xie, Wei‐Chen Zheng, Hui Chen, Shi-Shi Liu, Hua-yu Huang, Ying Zhong, Juntao Li, Rena Oh, Xiaoyang Huang, Wen‐Feng Lin, Ling Huang, Shi‐Gang Sun
Abstract
Abstract Controlling nucleation and growth of Li is crucial to avoid dendrite formation for practical applications of lithium metal batteries. Li 2 S has been exemplified to promote Li transport, but its crystal orientation significantly influences the Li deposition behaviors. Here, we investigate the interactions between Li and various surface structures of Li 2 S, and reveal that the Li 2 S(111) plane exhibits the highest Li affinity and the lowest diffusion barrier, leading to dense Li deposition. Using sulfur defect engineering for Li 2 S crystal orientation control, we construct three-dimensional vertically oriented Li 2 S(111)@Cu nanorod arrays as a Li metal electrode substrate and identify a substrate-dependent Li nucleation process and a facet-dependent growth mode. Furthermore, we demonstrate the versatility of the Li 2 S(111)@Cu substrate when paired with two positive electrodes: achieving an initial discharge capacity of 138.8 mAh g –1 with 88% capacity retention after 400 cycles at 83.5 mA g –1 with LiFePO 4 , and an initial discharge capacity of 181 mAh g –1 with 80% capacity retention after 160 cycles at 60 mA g –1 with commercial LiNi 0.8 Co 0.1 Mn 0.1 O 2 positive electrode (4 mAh cm –2 ).