TY - JOUR
T1 - Restraining the Jahn-Teller Distortion in Mn-Based Layered Cathodes toward High-Performance Potassium-Ion Batteries
AU - Tang, Yongwei
AU - Liu, Haoliang
AU - Zhu, Xu
AU - Liu, Mengting
AU - Tang, Wenjie
AU - Wei, Guang Xu
AU - Feng, Yi Hu
AU - Xiao, Bing
AU - Wang, Peng Fei
N1 - Publisher Copyright:
© 2025 American Chemical Society.
PY - 2025/6/10
Y1 - 2025/6/10
N2 - Mn-based layered oxides are regarded as a promising cathode candidate for potassium-ion batteries (PIBs) due to their high theoretical capacity and low cost. However, the cooperative Jahn-Teller distortion (CJTD) derived from six-coordinated high-spin Mn (III) (t2g3-eg1) centers is a serious issue that induces severe structural instability such as irreversible phase transformations, structural degradation, and Mn dissolution, thus deteriorating their cycling life during repeated charge and discharge processes. Herein, a P3-K0.4Li0.1Fe0.1Mn0.8O2 (KLFMO) cathode material is designed to regulate CJTD and corresponding electronic structures through quantifying occupancy in the dx2-y2 and dz2 orbitals of Mn. The synergistic incorporation of Li and Fe suppresses Mn (3d-eg*) orbital splitting, which contributes to restrained Jahn-Teller distortion of MnO6, enlarged K layer spacings, and contracted transition-metal slabs. Therefore, the detrimental phase transition from P3 to O3, local strain concentration, inhomogeneous surface structure reconstruction, and severe manganese dissolution are significantly alleviated due to the suppressed CJTD. Consequently, the target KLFMO cathode achieves a high capacity of 110.2 mA h g-1 at 0.2C and great cycling stability with 84.2% capacity retention after 150 cycles at 0.6C. Our findings provide an effective method to develop stable 3d transition-metal compounds free from the Jahn-Teller effect for advanced secondary batteries.
AB - Mn-based layered oxides are regarded as a promising cathode candidate for potassium-ion batteries (PIBs) due to their high theoretical capacity and low cost. However, the cooperative Jahn-Teller distortion (CJTD) derived from six-coordinated high-spin Mn (III) (t2g3-eg1) centers is a serious issue that induces severe structural instability such as irreversible phase transformations, structural degradation, and Mn dissolution, thus deteriorating their cycling life during repeated charge and discharge processes. Herein, a P3-K0.4Li0.1Fe0.1Mn0.8O2 (KLFMO) cathode material is designed to regulate CJTD and corresponding electronic structures through quantifying occupancy in the dx2-y2 and dz2 orbitals of Mn. The synergistic incorporation of Li and Fe suppresses Mn (3d-eg*) orbital splitting, which contributes to restrained Jahn-Teller distortion of MnO6, enlarged K layer spacings, and contracted transition-metal slabs. Therefore, the detrimental phase transition from P3 to O3, local strain concentration, inhomogeneous surface structure reconstruction, and severe manganese dissolution are significantly alleviated due to the suppressed CJTD. Consequently, the target KLFMO cathode achieves a high capacity of 110.2 mA h g-1 at 0.2C and great cycling stability with 84.2% capacity retention after 150 cycles at 0.6C. Our findings provide an effective method to develop stable 3d transition-metal compounds free from the Jahn-Teller effect for advanced secondary batteries.
KW - Jahn−Teller distortion
KW - Mn-based oxides
KW - cathode
KW - potassium-ion batteries
KW - structure degradation
UR - https://www.scopus.com/pages/publications/105007327071
U2 - 10.1021/acsnano.5c05389
DO - 10.1021/acsnano.5c05389
M3 - 文章
C2 - 40450682
AN - SCOPUS:105007327071
SN - 1936-0851
VL - 19
SP - 21118
EP - 21129
JO - ACS Nano
JF - ACS Nano
IS - 22
ER -