Mixed Polyanionic Compounds as Positive Electrodes for Low‐Cost Electrochemical Energy Storage

Abstract

Low‐cost electrochemical energy storage systems (EESSs) are urgently needed to promote the application of renewable energy sources such as wind and solar energy. In analogy to lithium‐ion batteries, the cost of EESSs depends mainly on charge‐carrier ions and redox centers in electrodes, and their performance is limited by positive electrodes. In this context, this Minireview evaluates several EESS candidates and summarizes the known mixed polyanionic compounds (MPCs)—a family with robust frameworks and large channels for ion storage and migration. After comprehensive analysis, it is pointed out that a deeper exploration of MPCs may generate numerous novel crystallographically interesting compounds and excellent cathode materials for low‐cost energy storage applications.

Mixed Polyanion Na‐Mn‐V‐P Glass–Ceramic Cathode Network: Improved Electrochemical Performance and Stability

“…These critical features result in good capacity retention for longer durations. [ 13–22 ] However, other issues such as low electrical conductivity, poor stability, and rate capability still need improvement. [ 16–22 ] Our group has successfully improved the electrochemical performance of a wide variety of amorphous‐based glass and glass–ceramic‐based cathode components to meet these gaps and limitations.…”

Recent Progress and Prospects of Layered Cathode Materials for Potassium‐ion Batteries

“…[ 146 ] Lan et al recently summarized some mixed polyanionic compounds with robust frameworks and large channels for ion storage and migration, such as layered K 2 [(VO) 2 (HPO 3 ) 2 (C 2 O 4 )] and KFePO 4 NO 3 (Figure 17b,c). [ 147 ] These materials have not been sufficiently explored as cathode materials in PIBs. If properly designed, some new compounds with convincing electrochemical properties can be expected.…”

“…[ 146 ] Copyright 2013, Elsevier. b) K 2 [(VO) 2 (HPO 3 ) 2 (C 2 O 4 )], and c) KFePO 4 NO 3 ; Reproduced with permission [ 147 ] Copyright 2020, Wiley‐VCH. d) XRD pattern of K 3 V 2 (PO 4 ) 3 , Reproduced with permission.…”

A novel low-cost and environment-friendly cathode with large channels and high structure stability for potassium-ion storage

“…tracted more attention owing to their favorable working potentials, rigid structural frameworks for K ion movement and high stability against organic solvents. Especially, polyanions based on iron are more competitive than others, thanks to its large abundance and environmental friendliness [27,28]. Besides, the selection of polyanionic groups is also critical to constructing a highperformance polyanionic cathode.…”