Boosting the Electrochemical Performance of Li- and Mn-Rich Cathodes by a Three-in-One Strategy

• Published in: Nano-micro letters Vol. 13; no. 1; p. 205
• Main Authors: He, Wei, Ye, Fangjun, Lin, Jie, Wang, Qian, Xie, Qingshui, Pei, Fei, Zhang, Chenying, Liu, Pengfei, Li, Xiuwan, Wang, Laisen, Qu, Baihua, Peng, Dong-Liang
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.12.2021; Springer Nature B.V; SpringerOpen
• Subjects: Accumulation; Attenuation; Banded structure; Big Data; Cathodes; Cation–polyanion co-doping; Chemistry; Crystal defects; Crystal structure; Cycles; Decay rate; Defect and stress engineering; Defects; Doping; Electrochemical analysis; Electrochemical performance; Energy storage; Engineering; Fourier transforms; Good structure stability; Laboratories; Layered materials; Li- and Mn-rich cathodes; Li-ion batteries; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; Parameter modification; Polyelectrolytes; Retention; Voltage stability; Li- and Mn-rich cathodes; Cation–polyanion co-doping; Good structure stability; Electrochemical performance; Defect and stress engineering
• ISSN: 2311-6706; 2150-5551
• DOI: 10.1007/s40820-021-00725-0

Highlights A novel three-in-one method is put forward to prepare Li- and Mn-rich cathode. The stress evolution of layered materials during cycling is characterized. The capacity and voltage stability are enhanced greatly. There are plenty of issues need to be solved before the practical application of Li- and Mn-rich cathodes, including the detrimental voltage decay and mediocre rate capability, etc. Element doping can effectively solve the above problems, but cause the loss of capacity. The introduction of appropriate defects can compensate the capacity loss; however, it will lead to structural mismatch and stress accumulation. Herein, a three-in-one method that combines cation–polyanion co-doping, defect construction, and stress engineering is proposed. The co-doped Na + /SO 4 2− can stabilize the layer framework and enhance the capacity and voltage stability. The induced defects would activate more reaction sites and promote the electrochemical performance. Meanwhile, the unique alternately distributed defect bands and crystal bands structure can alleviate the stress accumulation caused by changes of cell parameters upon cycling. Consequently, the modified sample retains a capacity of 273 mAh g −1 with a high-capacity retention of 94.1% after 100 cycles at 0.2 C, and 152 mAh g −1 after 1000 cycles at 2 C, the corresponding voltage attenuation is less than 0.907 mV per cycle.