High‐Energy Aqueous Sodium‐Ion Batteries

Electrolyte Interphases in Aqueous Batteries

The narrow electrochemical stability window of water poses a challenge to the development of aqueous electrolytes. In contrast to non-aqueous electrolytes, the products of water electrolysis do not contribute to the formation of a passivation layer on electrodes. As a result, aqueous electrolytes require the reactions of additional components, such as additives and co-solvents, to facilitate the formation of the desired solid electrolyte interphase (SEI) on the anode and cathode electrolyte interphase (CEI) on the cathode. This review highlights the fundamental principles and recent advancements in generating electrolyte interphases in aqueous batteries.

Material Design and Energy Storage Mechanism of Mn-Based Cathodes for Aqueous Zinc-Ion Batteries

Mn-based cathodes have been widely explored for aqueous zinc-ion batteries (ZIBs), by virtue of their high theoretical capacity and low cost. However, Mn-based cathodes suffer from poor rate capability and cycling performance. Researchers have presented various approaches to address these issues. Therefore, these endeavors scattered in various directions (e. g., designing electrode structures, defect engineering and optimizing electrolytes) are necessary to be connected through a systematic review. Hence, we comprehensively overview Mn-based cathode materials for ZIBs from the aspects of phase compositions, electrochemical behaviors and energy storage mechanisms, and try to build internal relations between these factors. Modification strategies of Mn-based cathodes are then introduced. Furthermore, this review also provides some new perspectives on future efforts toward high-energy and long-life Mn-based cathodes for ZIBs.

Solvation Effect on the Improved Sodium Storage Performance of N-Heteropentacenequinone for Sodium-Ion Batteries

The performance of electrode material is correlated with the choice of electrolyte, however, how the solvation has significant impact on electrochemical behavior is underdeveloped. Herein, N-heteropentacenequinone (TAPQ) is investigated to reveal the solvation effect on the performance of sodium-ion batteries in different electrolyte environment. TAPQ cycled in diglyme-based electrolyte exhibits superior electrochemical performance, but experiences a rapid capacity fading in carbonate-based electrolyte. The function of solvation effect is mainly embodied in two aspects: one is the stabilization of anion intermediate via the compatibility of electrode and electrolyte, the other is the interfacial electrochemical characteristics influenced by solvation sheath structure. By revealing the failure mechanism, this work presents an avenue for better understanding electrochemical behavior and enhancing performance from the angle of solvation effect.