武汉理工大学安琴友团队报道了钒氧化物中界面化学和配位结构的耦合操纵实现镁离子的快速扩散动力学。相关研究成果于2024年8月30日发表在《德国应用化学》。

可充电镁电池（RMBs）因其高容量和本质安全性而成为一种极具前景的储能系统。然而，缓慢的Mg²⁺扩散动力学阻碍了RMBs的实际发展，包括在阴极电解质界面（CEI）和阴极本体内。

该文中，研究人员提出了一种有效的策略来操纵低聚V₂O₅（L-V₂O₅）中的界面化学和配位结构，以实现快速的Mg²⁺扩散动力学。在界面化学方面，L-V₂O₅中特定的暴露晶面具有很强的供电子能力，这有助于促进电解质中C-F/C-S键的降解动力学，从而建立无机-有机互锁CEI层，实现Mg²⁺的快速扩散。

在配位结构方面，L-V₂O₅中矫直的V-O结构为加速Mg²⁺在阴极中的扩散提供了有效的离子扩散路径。因此，L-V₂O₅具有高可逆容量（在0.1A g^-1下为355.3mA h g^-1）和优异的倍率性能（在1A g^-1下为161mAh g^-1）。令人印象深刻的是，首次组装成功的叉指式微型RMBs展现出卓越的灵活性和实用性。

该项工作为开发高动力学RMBs的界面和内部离子扩散提供了更深入的见解。

附：英文原文

Title: Coupling Manipulation of Interfacial Chemistry and Coordination Structure in Vanadium Oxides Enables Rapid Magnesium Ion Diffusion Kinetics

Author: Weixiao Wang, Wenwen Wang, Fangyu Xiong, Jiashen Meng, Jinsong Wu, Wei Yang, Juncai Long, Jinghui Chen, Jiajun Chen, Qinyou An

Issue&Volume: 2024-08-30

Abstract: Rechargeable magnesium batteries (RMBs) are a highly promising energy storage system due to their high volumetric capacity and intrinsic safety. However, the practical development of RMBs is hindered by the sluggish Mg2+ diffusion kinetics, including at the cathode-electrolyte interface (CEI) and within the cathode bulk. Herein, we propose an efficient strategy to manipulate the interfacial chemistry and coordination structure in oligolayered V2O5 (L-V2O5) for achieving rapid Mg2+ diffusion kinetics. In terms of the interfacial chemistry, the specific exposed crystal planes in L-V2O5 possess strong electron donating ability, which helps to promote the degradation dynamics of C–F/C–S bonds in the electrolyte, thereby establishing the inorganic-organic interlocking CEI layer for rapid Mg2+ diffusion. In terms of the coordination structure, the straightened V-O structure in L-V2O5 provides efficient ions diffusion path for accelerating Mg2+ diffusion in the cathode. As a result, the L-V2O5 delivers a high reversible capacity (355.3 mA h g1 at 0.1 A g1) and an excellent rate capability (161 mAh g1 at 1 A g1). Impressively, the interdigital micro-RMBs is firstly assembled, exhibiting excellent flexibility and practicability. This work gives deeper insights into the interface and interior ions diffusion for developing high-kinetics RMBs.

DOI: 10.1002/anie.202414119

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202414119