Nam Ki-Hun, Hwa Yoon, Park Cheol-Min
School of Materials Science and Engineering, Kumoh National Institute of Technology, 61 Daehak-ro, Gumi, Gyeongbuk 39177, Republic of Korea.
Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, United States.
ACS Appl Mater Interfaces. 2020 Apr 1;12(13):15053-15062. doi: 10.1021/acsami.9b21803. Epub 2020 Mar 23.
To design a high-performance sodium-ion battery anode, binary zinc phosphides (ZnP and ZnP) were synthesized by a facile solid-state heat treatment process, and their Na storage characteristics were evaluated. The Na reactivity of ZnP was better than that of ZnP. Therefore, a C-modified ZnP-based composite (ZnP-C) was fabricated to achieve better electrochemical performance. To investigate the electrochemical reaction mechanism of ZnP-C during sodiation/desodiation, various ex situ analytical techniques were employed. During sodiation, ZnP in the composite was transformed into NaZn and NaP phases, exhibiting a one-step conversion reaction. Conversely, Zn and P in NaZn and NaP, respectively, were fully recombined to the original ZnP phase during desodiation. Owing to the one-step conversion/recombination of ZnP in the composite during cycling, the ZnP-C showed high electrochemical performance with a highly reversible capacity of 883 mA h g after 130 cycles with no capacity deterioration and a fast C-rate capability of 500 mA h g at 1 C and 350 mA h g at 3 C.
为设计一种高性能钠离子电池负极，通过简便的固态热处理工艺合成了二元磷化锌（ZnP和ZnP），并对其储钠特性进行了评估。ZnP的钠反应活性优于ZnP。因此，制备了一种碳改性的ZnP基复合材料（ZnP-C）以实现更好的电化学性能。为研究ZnP-C在 sodiation/脱 sodiation 过程中的电化学反应机理，采用了各种非原位分析技术。在 sodiation 过程中，复合材料中的ZnP转变为NaZn和NaP相，呈现一步转化反应。相反，在脱 sodiation 过程中，NaZn和NaP中的Zn和P分别完全重新组合成原始的ZnP相。由于复合材料中的ZnP在循环过程中进行一步转化/重组，ZnP-C表现出高电化学性能，在130次循环后具有883 mA h g的高可逆容量且无容量衰减，在1 C时具有500 mA h g的快速C倍率能力，在3 C时具有350 mA h g的快速C倍率能力。
