Investigating Particle Size‐Dependent Redox Kinetics and Charge Distribution in Disordered Rocksalt Cathodes
Investigating Particle Size‐Dependent Redox Kinetics and Charge Distribution in Disordered Rocksalt Cathodes
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DOI：
10.1002/adfm.202110502
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发表时间：
2022-02
影响因子：
19
通讯作者：
Yuxin Zhang;Anyang Hu;Jue Liu;Zhengrui Xu;Linqin Mu;Sami Sainio;D. Nordlund;Luxi Li;Cheng-Jun Sun;Xianghui Xiao;Yijin Liu;Feng Lin
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作者：
Yuxin Zhang;Anyang Hu;Jue Liu;Zhengrui Xu;Linqin Mu;Sami Sainio;D. Nordlund;Luxi Li;Cheng-Jun Sun;Xianghui Xiao;Yijin Liu;Feng Lin
了解各种氧化还原活动如何在无序岩盐氧化物（DRX）中演变和分布，可以深入了解操纵材料特性以实现稳定的高能电池。在此，作者提出了如何反应动力学和氧化还原活性的空间分布由DRX材料的粒径。尺寸相关的电化学性能归因于不同尺寸下不同的阳离子和阴离子反应动力学，可以定制以实现最佳容量和稳定性。总的来说，DRX颗粒中的局部带电域显示由各向同性脱锂途径引起的随机异质性。由于动力学限制，微米级颗粒表现出整体的“核-壳”电荷分布，而亚微米颗粒在整个颗粒和整体中表现出更均匀的氧化还原反应。亚微米DRX颗粒表现出增加的阴离子氧化还原活性，但循环稳定性较差。总之，工程粒度可以有效地调节阳离子和阴离子氧化还原活性如何在DRX材料中演变和分布。
Understanding how various redox activities evolve and distribute in disordered rocksalt oxides (DRX) can advance insights into manipulating materials properties for achieving stable, high‐energy batteries. Herein, the authors present how the reaction kinetics and spatial distribution of redox activities are governed by the particle size of DRX materials. The size‐dependent electrochemical performance is attributed to the distinct cationic and anionic reaction kinetics at different sizes, which can be tailored to achieve optimal capacity and stability. Overall, the local charged domains in DRX particles display random heterogeneity caused by the isotropic delithiation pathways. Owing to the kinetic limitation, the micron‐sized particles exhibit a holistic “core‐shell” charge distribution, whereas sub‐micron particles show more uniform redox reactions throughout the particles and ensembles. Sub‐micron DRX particles exhibit increasing anionic redox activities yet inferior cycling stability. In summary, engineering particle size can effectively modulate how cationic and anionic redox activities evolve and distribute in DRX materials.