Regulating <i>f</i> orbital of Tb electronic reservoir to activate stepwise and dual‐directional sulfur conversion reaction
Shuang Yu, Shuo Yang, Dong Cai, Huagui Nie, Xuemei Zhou, Tingting Li, Ce Liang, Haohao Wang, Yangyang Dong, Rui Xu, Guoyong Fang, Jinjie Qian, Yongjie Ge, Yue Hu, Zhi Yang
Abstract
Abstract The sluggish kinetics in multistep sulfur redox reaction with different energy requirements for each step, is considered as the crucial handicap of lithium–sulfur (Li–S) batteries. Designing an electron reservoir, which can dynamically release electron to/accept electron from sulfur species during discharge/charge, is the ideal strategy for realizing stepwise and dual‐directional polysulfide electrocatalysis. Herein, a single Tb 3+/4+ oxide with moderate unfilled f orbital is synthetized as an electron reservoir to optimize polysulfide adsorption via Tb–S and N···Li bonds, reduce activation energy barrier, expedite electron/Li + transport, and selectively catalyze both long‐chain and short‐chain polysulfide conversions during charge and discharge. As a result, Tb electron reservoir enables stable operation of low‐capacity decay (0.087% over 500 cycles at 1 C), high sulfur loading (5.2 mg cm −2 ) and electrolyte‐starved (7.5 μL mg −1 ) Li–S batteries. This work could unlock the potential of f orbital engineering for high‐energy battery systems. image