Liu Hengjun, Zou Feihu, Liao Shuxuan, Pan Yuanyuan, Zhao Zhiqiang, Gu Fangchao, Xu Xixiang, Sang Xiancheng, Han Yuanyuan, Bu Zeyuan, Qin Lihao, Wang Yukui, Chen Guihuan, Ruan Mingyue, Li Qinghao, Hu Han, Li Qiang
College of Physics, Weihai Innovation Research Institute, College of Materials, Qingdao University, Qingdao 266071, China.
State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China.
J Phys Chem Lett. 2024 May 2;15(17):4694-4704. doi: 10.1021/acs.jpclett.4c00760. Epub 2024 Apr 24.
Batteries with intercalation-conversion-type electrodes tend to achieve high-capacity storage, but the complicated reaction process often suffers from confusing electrochemical mechanisms. Here, we reinterpreted the essential issue about the potential of the conversion reaction and whether there is an intercalation reaction in a lithium/sodium-ion battery (LIB/SIB) with the FeP anode based on the evolution of the magnetic phase. Especially, the ever-present intercalation process in a large voltage range followed by the conversion reaction with extremely low potential was confirmed in FeP LIB, while it is mainly the conversion reaction for the sodium storage mechanism in FeP SIB. The insufficient conversion reaction profoundly limits the actual capacity to the expectedly respectable value. Accordingly, a graphene oxide modification strategy was proposed to increase the reversible capacity of FeP LIB/SIB by 99% and 132%, respectively. The results facilitate the development of anode materials with a high capacity and low operating potential.
具有嵌入-转换型电极的电池往往能够实现高容量存储，但复杂的反应过程常常伴随着令人困惑的电化学机制。在此，我们基于磁相的演变，重新解释了关于基于FeP负极的锂/钠离子电池（LIB/SIB）中转换反应电位以及是否存在嵌入反应的关键问题。特别是，在FeP LIB中证实了在大电压范围内始终存在的嵌入过程，随后是具有极低电位的转换反应，而在FeP SIB中，钠存储机制主要是转换反应。转换反应的不足严重限制了实际容量达到预期的可观值。因此，提出了一种氧化石墨烯改性策略，分别将FeP LIB/SIB的可逆容量提高了99%和132%。这些结果有助于开发具有高容量和低工作电位的负极材料。
