TY - JOUR
T1 - Deciphering Metastable Structure Evolution in Voltage Hysteresis of Lithium-Rich Cathodes
AU - Xue, Haoyu
AU - Zhao, Wenguang
AU - Zhan, Minzhi
AU - Zhou, Dong
AU - Zhang, Nian
AU - Chen, Zhefeng
AU - Qi, Rui
AU - Chu, Mihai
AU - Li, Shunning
AU - Wang, Jun
AU - Liu, Qi
AU - Pan, Feng
AU - Zhang, Mingjian
PY - 2026/3/3
Y1 - 2026/3/3
N2 - Voltage hysteresis, as one of the main concerns in lithium-rich oxides (LROs), significantly deteriorates the energy conversion efficiency and hinders its application in high-energy-density Li-ion batteries. Nevertheless, the structural origin of voltage hysteresis has still not been clarified. Here we reveal the thermodynamically metastable structure evolution, particularly negative thermal expansion and correlated transition-metal (TM) octahedral (TMO6) distortion release, during thermally driven voltage hysteresis recovery in LROs. Moreover, whole exothermic structure evolution and related voltage recovery are linked: (1) abnormal negative thermal expansion below 200 °C due to the relief of octahedral distortion, which leads to a voltage recovery by 0.26 V; (2) reconstruction of Li@Mn6 superstructure units due to Li-vacancy-assisted TM migration at 300 °C, which further recovers the voltage by 0.16 V and the oxygen plateau. Our work provides a more elaborate picture of the structure–voltage correlation in anionic-redox systems and highlights that these two structural variations form a metastable phase, serving as a solid base after the first cycle for subsequent cycling in LROs. © 2026 American Chemical Society
AB - Voltage hysteresis, as one of the main concerns in lithium-rich oxides (LROs), significantly deteriorates the energy conversion efficiency and hinders its application in high-energy-density Li-ion batteries. Nevertheless, the structural origin of voltage hysteresis has still not been clarified. Here we reveal the thermodynamically metastable structure evolution, particularly negative thermal expansion and correlated transition-metal (TM) octahedral (TMO6) distortion release, during thermally driven voltage hysteresis recovery in LROs. Moreover, whole exothermic structure evolution and related voltage recovery are linked: (1) abnormal negative thermal expansion below 200 °C due to the relief of octahedral distortion, which leads to a voltage recovery by 0.26 V; (2) reconstruction of Li@Mn6 superstructure units due to Li-vacancy-assisted TM migration at 300 °C, which further recovers the voltage by 0.16 V and the oxygen plateau. Our work provides a more elaborate picture of the structure–voltage correlation in anionic-redox systems and highlights that these two structural variations form a metastable phase, serving as a solid base after the first cycle for subsequent cycling in LROs. © 2026 American Chemical Society
KW - negative thermal expansion
KW - octahedral distortion
KW - thermal treatment
KW - TM migration
KW - voltage hysteresis
UR - https://www.scopus.com/pages/publications/105031689603
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-105031689603&origin=recordpage
U2 - 10.1021/acsnano.5c20611
DO - 10.1021/acsnano.5c20611
M3 - RGC 21 - Publication in refereed journal
C2 - 41703791
SN - 1936-0851
VL - 20
SP - 7205
EP - 7215
JO - ACS Nano
JF - ACS Nano
IS - 8
ER -