TY - JOUR
T1 - Ionic-Size-Dependent Reversible Interlayer Cation Migration and Voltage Hysteresis in P2-Type Sodium Layered Cathodes
AU - Jiao, Jiahao
AU - Hua, Ze
AU - Shen, Feiran
AU - Ren, Hongjin
AU - Zhou, Yue
AU - Niu, Yilong
AU - Cui, Tianwei
AU - Wang, Yuan
AU - Bi, Haibo
AU - Zuo, Yuxuan
AU - Kao, Cheng Wei
AU - Chan, Ting Shan
AU - Chen, Zhenhua
AU - Zhang, Liang
AU - Wang, Qing
AU - He, Lunhua
AU - Ning, Fanghua
AU - Shao, Ruiwen
AU - Li, Biao
N1 - Publisher Copyright:
© 2026 American Chemical Society
PY - 2026/7/1
Y1 - 2026/7/1
N2 - Voltage hysteresis in layered oxide cathodes of Li/Na-ion batteries, a significant barrier to energy efficiency, is commonly attributed to reversible cation migration. This is particularly prevalent in materials utilizing anionic redox for high capacity, yet the strong coupling between cation migration and complex anionic processes (such as O–O dimerization, oxygen loss, and charge transfer) has obscured a definitive causal link. To decouple these phenomena, we designed a series of P2-type Na2/3Ni0.1M0.1Mn0.8O2 compounds, where M is an electrochemically inactive trivalent cation (Al3+, Ga3+, Sc3+) of increasing ionic radius (0.535 Å, 0.62 Å, 0.745 Å). Interestingly, these systems exhibit negligible anionic redox activity but display increasing voltage hysteresis that scales with the size of the M3+ cations. Through a combination of experimental and theoretical analyses, we correlate this hysteresis with an enhanced tendency for reversible interlayer cation migration of M3+, which is facilitated by a larger cationic size that is more adaptive to the large Na interlayer spacing. By successfully isolating cation migration from anionic redox, this work establishes its direct role in driving voltage hysteresis, providing fundamental insights into the design of cathode materials having less cation migration and reduced voltage hysteresis for Na-ion batteries.
AB - Voltage hysteresis in layered oxide cathodes of Li/Na-ion batteries, a significant barrier to energy efficiency, is commonly attributed to reversible cation migration. This is particularly prevalent in materials utilizing anionic redox for high capacity, yet the strong coupling between cation migration and complex anionic processes (such as O–O dimerization, oxygen loss, and charge transfer) has obscured a definitive causal link. To decouple these phenomena, we designed a series of P2-type Na2/3Ni0.1M0.1Mn0.8O2 compounds, where M is an electrochemically inactive trivalent cation (Al3+, Ga3+, Sc3+) of increasing ionic radius (0.535 Å, 0.62 Å, 0.745 Å). Interestingly, these systems exhibit negligible anionic redox activity but display increasing voltage hysteresis that scales with the size of the M3+ cations. Through a combination of experimental and theoretical analyses, we correlate this hysteresis with an enhanced tendency for reversible interlayer cation migration of M3+, which is facilitated by a larger cationic size that is more adaptive to the large Na interlayer spacing. By successfully isolating cation migration from anionic redox, this work establishes its direct role in driving voltage hysteresis, providing fundamental insights into the design of cathode materials having less cation migration and reduced voltage hysteresis for Na-ion batteries.
UR - https://www.scopus.com/pages/publications/105043535560
U2 - 10.1021/jacs.6c02072
DO - 10.1021/jacs.6c02072
M3 - Article
C2 - 42310999
AN - SCOPUS:105043535560
SN - 0002-7863
VL - 148
SP - 25577
EP - 25588
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 25
ER -