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

Wei He; Fangjun Ye; Jie Lin; Qian Wang; Qingshui Xie; Fei Pei; Chenying Zhang; Pengfei Liu; Xiuwan Li; Laisen Wang; Baihua Qu; Dong-Liang Peng

doi:10.1007/s40820-021-00725-0

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

Nanomicro Lett. 2021 Oct 11;13(1):205. doi: 10.1007/s40820-021-00725-0.

Authors

Wei He¹, Fangjun Ye¹, Jie Lin¹, Qian Wang¹, Qingshui Xie^{2

3}, Fei Pei⁴, Chenying Zhang¹, Pengfei Liu⁵, Xiuwan Li⁶, Laisen Wang⁷, Baihua Qu^{8

9}, Dong-Liang Peng¹

Affiliations

¹ State Key Lab of Physical Chemistry of Solid Surface, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials and Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, People's Republic of China.
² State Key Lab of Physical Chemistry of Solid Surface, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials and Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, People's Republic of China. xieqsh@xmu.edu.cn.
³ Shenzhen Research Institute of Xiamen University, Shenzhen, 518000, People's Republic of China. xieqsh@xmu.edu.cn.
⁴ College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.
⁵ Zhengzhou Key Laboratory of Big Data Analysis and Application, Henan Academy of Big Data, Zhengzhou University, Zhengzhou, 450002, People's Republic of China.
⁶ Fujian Provincial Key Laboratory of Light Propagation and Transformation, College of Information Science and Engineering, Huaqiao University, Xiamen, 361021, People's Republic of China.
⁷ State Key Lab of Physical Chemistry of Solid Surface, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials and Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, People's Republic of China. wangls@xmu.edu.cn.
⁸ State Key Lab of Physical Chemistry of Solid Surface, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials and Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, People's Republic of China. bhqu@xmu.edu.cn.
⁹ Shenzhen Research Institute of Xiamen University, Shenzhen, 518000, People's Republic of China. bhqu@xmu.edu.cn.

Abstract

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⁺/SO₄^2- 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.

Keywords: Cation–polyanion co-doping; Defect and stress engineering; Electrochemical performance; Good structure stability; Li- and Mn-rich cathodes.