Boosting High-Voltage and Ultralong-Cycling Performance of Single-Crystal LiNi 0.5 Co 0.2 Mn 0.3 O 2 Cathode Materials via Three-in-One Modification

Energy & Environmental Materials

article

Bao Zhang¹  Jixue Shen¹  Qi Wang¹  Changqing Hu³  Bi Luo¹  Yun Liu¹  Zhiming Xiao¹  Xing Ou¹ 

[1] Engineering Research Center of the Ministry of Education for Advanced Battery Materials, School of Metallurgy and Environment, Central South University;Zhejiang Power New Energy Co. Ltd.;Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering, Beijing Institute of Technology

关键词: Al2O3/Li3BO3 dual-coating;    Li-ion batteries;    Na doping;    single-crystal cathode;    three-in-one modification;   

DOI  :  10.1002/eem2.12270

来源: Wiley

【 摘 要 】

LiNi0.5Co0.2Mn0.3O2 is extensively researched as one of the most widely used commercially materials for Li-ion batteries at present. However, the poor high-voltage performance (≥4.3 V) with low reversible capacity limits its replacement for LiCoO2 in high-end digital field. Herein, three-in-one modification, Na-doping and Al2O3@Li3BO3 dual-coating simultaneously, is explored for single-crystalline LiNi0.5Co0.2Mn0.3O2 (N-NCM@AB), which exhibits excellent high-voltage performance. N-NCM@AB displays a discharge-specific capacity of 201.8 mAh g−1 at 0.2 C with a high upper voltage of 4.6 V and maintains 158.9 mAh g−1 discharge capacity at 1 C over 200 cycles with the corresponding capacity retention of 87.8%. Remarkably, the N-NCM@AB ||graphite pouch-type full cell retains 81.2% of its initial capacity with high working voltage of 4.4 V over 1600 cycles. More importantly, the fundamental understandings of three-in-one modification on surface morphology, crystal structure, and phase transformation of N-NCM@AB are clearly revealed. The Na+ doped into the Li–O slab can enhance the bond energy, stabilize the crystal structure, and facilitate Li+ transport. Additionally, the interior surface layer of Li+-ions conductor Li3BO3 relieves the charge transfer resistance with surface coating, whereas the outer surface Al2O3 coating layer is beneficial for reducing the active materials loss and alleviating the electrode/electrolyte parasite reaction. This three-in-one strategy provides a reference for the further research on the performance attenuation mechanism of NCM, paving a new avenue to boost the high-voltage performance of NCM cathode in Li-ion batteries.

【 授权许可】

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