Park Jae Yeol Jo, Minji Hong, Seungki Park, Seunggyu Park, Jae-Ho Kim, Yong-Il Kim, Sang-Ok Chung, Kyung Yoon Byun, Dongjin Kim, Seung Min Chang, Wonyoung 2024-01-19T11:32:32Z 2024-01-19T11:32:32Z 2022-06-17 2022-08 1614-6832 https://pubs.kist.re.kr/handle/201004/114839 The authors reveal the mechanisms of degradation of capacity, charge voltage, and discharge voltage of commercially-available high-nickel cathode material when it is cycled without a voltage margin by two different charge protocols: constant-current charging and constant-current, constant-voltage charging. With repeated constant-current charging, the cathode material changes to a non-periodic cation-mixed state, which causes a relatively low voltage degradation, whereas during constant-current, constant-voltage charging, the cathode material changes from a layered structure to a periodic cation-mixed spinel-like phase, with consequent severe voltage decay. This decay results from a reduction in the equilibrium electrode potential and an increase of overpotential which are aggravated in a periodic cation-mixed state. The findings provide insights into the use of excess Li without charge-voltage margin in high-Ni cathode materials. English Wiley-VCH Verlag Mechanism of Degradation of Capacity and Charge/Discharge Voltages of High-Ni Cathode During Fast Long-Term Cycling Without Voltage Margin Article 10.1002/aenm.202201151 1 Advanced Energy Materials, v.12, no.29 Advanced Energy Materials 12 29 N scie scopus 000806730100001 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Energy & Fuels Materials Science Physics Article ELECTRIC VEHICLE LITHIUM STATE OXIDE FADE cation mixing electrode potential high-nickel cathodes lithium-ion batteries overpotential STEM