V‐Induced Low‐Spin State Mn 3+ Suppresses Jahn–Teller Distortion for High‐Performance Aqueous Zinc Ion Batteries

作者：Jin Ma, Chen Li, Qianqian Ji, Chenglong Liu, Bing Tang, Ruiqi Liu, Yuying Liu, Na Li, Chao Wang, Jianrong Zeng, Kun Zheng, Wensheng Yan · 发表于：Angewandte Chemie International Edition · 年份：2025 · DOI：10.1002/anie.202513148 · 被引用次数：20 · 研究领域：Advanced battery technologies research、Advanced Battery Materials and Technologies、Perovskite Materials and Applications

Abstract The Jahn–Teller distortion caused by high‐spin state Mn 3+ (t 2g 3 e g 1 ) is a major limiting factor for improving both the specific capacity and cycling stability of MnO 2 cathodes in aqueous zinc‐ion batteries. Thus, an intrinsic strategy for optimizing MnO 2 involves the effective elimination of the high‐spin state Mn 3+ (t 2g 3 e g 1 ) during electrochemical process. Herein, we focus on structural design that constructed NH 4 V 3 O 8 ‐coated MnO 2 (Mn@V) nanorods to achieve the low‐spin state of Mn 3+ (t 2g 4 e g 0 ) and inhibit the Jahn–Teller distortion. The well‐designed Mn@V cathode exhibits outstanding specific capacity (513.5 mAh g −1 at 0.2 A g −1 ), remarkable rate performance (205 mAh g −1 at 2.0 A g −1 ), and excellent cycling stability (201 mAh g −1 after 2000 cycles at 1.0 A g −1 ). Through a series of advanced characterization techniques, such as ex‐situ X‐ray absorption spectroscopy, combined with theoretical calculations, we systematically demonstrate that the NH 4 V 3 O 8 coating layer alters electron configuration through the V–O–Mn bridge bonds and induces the low‐spin state Mn 3+ (t 2g 4 e g 0 ) in MnO 2 , thereby suppressing the Jahn–Teller distortion and enhancing cycling stability. This study offers profound insights into the inhibition of the Jahn–Teller distortion from an electron spin perspective, and presents a facile approach to synergistically enhance specific capacity and cycling stability.