An effective strategy to enhance the electrochemical performance of LiNi0.6Mn0.2Co0.2O2: Optimizing a Li diffusion pathway via magnetic alignment of single-crystal cathode material under an ordinary 0.4-T magnetic field. Issue 21 (1st November 2022)

• Record Type: Journal Article
• Authors: Gao, Daichao; Yang, Jiaxin; Zhang, Dongyun; Chang, Chengkang
• Is Part Of: Ceramics international. Volume 48:Issue 21(2022)
• Page Start: 31598
• Page End: 31605
• Publication Date: 2022-11-01
• Subjects: NCM622 single-crystal cathode -- Magnetic-field orientation -- Capacity retention -- Rate performance; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.07.081
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: A strategy to enhance the electrochemical performance of a single-crystal LiNix Mny Coz O2 (NCM) electrode is proposed herein based on a preferred orientation of a Li diffusion pathway along the working direction under an ordinary 0.4-T magnetic field. Hexagonal NCM622 single crystals can be aligned along their crystallographic c-axis parallel to the applied magnetic field because the crystal has an easy magnetization axis along the c-axis. The horizontal magnetic field–oriented NCM622 cathode (HMFC) shows inhibited polarization and increased lithium-ion conductivity. The suppressed polarization promotes cyclability, increasing the specific capacity from 157.93 to 168.75 mAhg −1 after the 100th cycle at 0.5 C. Furthermore, the increased diffusion coefficient (from 3.06 × 10 −10 cm 2 s −1 to 7.12 × 10 −10 cm 2 s −1 ) causes substantial improvement in the rate performance, achieving a high specific capacity of 130.77 mAhg −1 at 10 C, while the electrode without magnetic treatment achieves a specific capacity of only 115.88 mAhg −1 . Owing to such a superior electrochemical performance, the HMFC electrodes show high potential for lithium-ion batteries in the EV industry. Decreasing the magnetic field from 6 to 0.4 T for cathode alignment facilitates the applicability of the proposed strategy to production lines of battery plants using commercially available permanent magnets because a magnetic field of 0.4 T is easily achievable. Graphical abstract: Image 1