南开大学陈军团队报道了消除阴极-电解质界面电荷转移用于钠离子电池超快动力学。相关研究成果发表在2024年10月17日出版的《美国化学会杂志》。

离子电池存在动力学问题，这是由于离子在电极-电解质界面上的缓慢传输造成的，在快速充电或低温运行过程中会导致能量快速衰减。增强动力学的一个令人兴奋的前景是构建类似神经元的电极，模拟神经系统中的快速信号传输。

人们认为，这些仿生设计增强了电极通过碳网络的电子/离子传输。然而，它们是否能够避免电极-电解质界面上缓慢的电荷转移仍然未知。

研究人员通过将碳纳米管的开口与碳包覆的Na₃V₂O₂(PO₄)₂F阴极纳米粒子的表面连接起来，使用碳纳米管来捕获充电过程中纳米粒子释放的Na⁺离子。因此，Na⁺的运动仅限于神经元状阴极内，消除了传统电池中几乎无法实现的电解质和阴极之间的离子传输。

因此，与未改性的阴极相比，界面电荷转移电阻降低了14倍，从而获得了优异的快速充电性能和高达200℃的优异循环性能，令人惊讶的是，在低至60℃的低温下无需电解质改性即可可逆运行，超过了迄今为止报道的其他Na₃V₂O₂(PO₄)₂F基电池。

由于200多年来电池的运行一直依赖于电极-电解质界面的电荷转移，该方法偏离了这种传统的离子传输范式，为构建在恶劣条件下工作的更好的电池铺平了道路。

附：英文原文

Title: Eliminating Charge Transfer at Cathode-Electrolyte Interface for Ultrafast Kinetics in Na-Ion Batteries

Author: Xue Huang, Haoxiang Sun, Xiangyi Li, Wenhao Zhu, Lei Chen, Tian Ma, Shulin Ding, Tao Ma, Yang Dong, Kai Zhang, Fangyi Cheng, Qiulong Wei, Lijun Gao, Jianqing Zhao, Wei Zhang, Jun Chen

Issue&Volume: October 17, 2024

Abstract: Sodium-ion batteries suffer from kinetic problems stemming from sluggish ion transport across the electrode–electrolyte interface, causing rapid energy decay during fast-charging or low-temperature operation. One exciting prospect to enhance kinetics is constructing neuron-like electrodes that emulate  fast signal transmission in a nervous system. It has been considered that these bioinspired designs enhance electron/ion transport of the electrodes through carbon networks. However, whether they can avoid  sluggish charge transfer at the electrode–electrolyte interface remains unknown. By connecting the openings of carbon nanotubes with the surface of carbon-coated Na3V2O2(PO4)2F cathode nanoparticles, here we use carbon nanotubes to trap Na+ ions released from the nanoparticles during charge. Therefore, Na+ movement is confined only inside the neuron-like cathode, eliminating ion transport between the electrolyte and cathode, which has been scarcely achieved in conventional batteries. As a result, a 14-fold reduction in interfacial charge transfer resistance is achieved when compared to unmodified cathodes, leading to superior fast-charging performance and excellent cyclability up to 200C, and surprisingly, reversible operation at low temperatures down to 60 °C without electrolyte modification, surpassing other Na3V2O2(PO4)2F-based batteries reported to date. As battery operation has relied on charge transfer at the electrode–electrolyte interface for over 200 years, our approach departs from this traditional ion transport paradigm, paving the way for building better batteries that work under harsh conditions.

DOI: 10.1021/jacs.4c08191

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c08191