Multi-Electron Reactions enabled by Anion-Based Redox Chemistry for High-Energy Multivalent Rechargeable Batteries
Z. Li , Bhaghavathi P. Vinayan , Piotr Jankowski , Christian Njel , Ananyo Roy , Tejs Vegge , Julia Maibach , Juan Maria García Lastra , Maximilian Fichtner , Zhirong Zhao-Karger
The development of multivalent metal (such as Mg and Ca) based battery systems is hindered by lack of suitable cathode chemistry that shows reversible multi-electron redox reactions. Cationic redox centres in the classical cathodes can only afford stepwise single-electron transfer, which are not ideal for multivalent-ion storage. The charge imbalance during multivalent ion insertion might lead to an additional kinetic barrier for ion mobility. Therefore, multivalent battery cathodes only exhibit slope-like voltage profiles with insertion/extraction redox of less than one electron. Taking VS4 as a model material, reversible two-electron redox with cationic–anionic contributions is verified in both rechargeable Mg batteries (RMBs) and rechargeable Ca batteries (RCBs). The corresponding cells exhibit high capacities of >300 mAh g−1 at a current density of 100 mA g−1 in both RMBs and RCBs, resulting in a high energy density of >300 Wh kg−1 for RMBs and >500 Wh kg−1 for RCBs. Mechanistic studies reveal a unique redox activity mainly at anionic sulfides moieties and fast Mg2+ ion diffusion kinetics enabled by the soft structure and flexible electron configuration of VS4.
|Journal series||Angewandte Chemie-International Edition, [Angewandte Chemie - International Edition], ISSN 1433-7851, e-ISSN 1521-3773|
|Score||= 200.0, 03-09-2020, ArticleFromJournal|
|Publication indicators||= 0; : 2018 = 2.132; : 2018 = 12.257 (2) - 2018=12.359 (5)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.