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| Research on In-Mg-Al Co-doped high voltage LiCoO2 cathode materials |
| LIU Zhuoqin1，ZHOU Xiaochong2，MO Liangjun1 |
| （1. Guangzhou Customs District Technology Center, Guangzhou, Guangzhou 510623, China; 2. Wanxiang 123
Co., Ltd, Hangzhou, Hangzhou 311215, China） |
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Abstract Due to its high energy density, lithium cobalt oxide (LiCoO2) cathode material is the mainstream of lithiumion
battery cathode material. However, the irreversible phase transformation and oxygen release under high
voltage can cause rapid capacity degradation and safety problems, which seriously restrict the practical application
of LiCoO2. In this study, In-Mg-Al co-doping was used to prepare the high voltage LiCoO2 cathode material. The
phase structure and surface morphology were studied by X-ray diffraction and scanning electron microscopy. Electrochemical
impedance spectroscopy was used to study the effect of element doping on solid electrolyte interphase
on the positive electrode surface. The electrochemical performance was evaluated by assembling LiCoO2/lithium
metal coin-type half cells and LiCoO2/graphite pouch-type full cells. With In-Mg-Al co-doping, the as-assembled
LiCoO2/lithium metal half cells delivere a 0.1C discharge capacity of 217.6 mAh/g in the range of 3-4.6 V, and
have better rate performances than the undoped and the Mg-Al co-doped LiCoO2 from 0.1 to 5C. The capacity retention
rate of the LiCoO2/graphite pouch-type full cell is 75.1% after 500 cycles at 1C.
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Received: 20 December 2021
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2022, Vol. 32 
