Batteries & Supercaps www.batteries-supercaps.org Review doi.org/10.1002/batt.202200160Multivalent secondary batteries (MSBs) have attracted great attention in view of their rich resources, low cost, and high safety. However, its development and application are still plagued by electrode materials. With their renewable and highly adjustable structures, organic electrode materials (OEMs) have several advantages over traditional inorganic electrode materials (IEMs), which has become the current research hotspot of electrode materials for MSBs. In this review, we present the recent developments in OEMs used for secondary batteries, including carbonyl compounds, imine compounds, conductive polymers, covalent organic frameworks, organic cyanides, organosulfur polymers and so on. An overview of the structural characteristics, energy storage mechanism, and electrochemical performance of OEMs in MSBs is given. Furthermore, to reveal the reasons for the high performance of the preponderant organic electrode materials, the relationships between material structures, electrolyte system, and battery properties are discussed in detail. Finally, we hope that this review could provide a fundamental guide to developing and designing high-performance MSBs in the future.

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Organic sodium-ion batteries (OSIBs) have become one of the most favorable contestants for use in energy storage systems. However, the practical applications of OSIBs are limited because the organic materials...

Organic cathode materials have the advantages of abundant raw materials, high theoretical specific capacity, controllable structure and easy recycling. Pyrene-4,5,9,10tetraone (PTO), as one of the typical organic cathode materials, achieves efficient storage and release of Na + . However, its good solubility in traditional organic liquid electrolytes is detrimental to the cyclic stability of batteries. To address this issue, the double-layer composite gel polymer electrolyte (DLCGPE) consisting of poly (ionic liquid) gel polymer electrolyte and plastic crystal electrolyte was developed and applied to organic sodium-metal batteries. This as-prepared DLCGPE displays an ionic conductivity of 2.17 × 10 À 4 S cm À 1 and an electrochemical window of 4.8 V. The as-fabricated sodium-symmetric batteries maintain interfacial stability after 500 h of cycling. Furthermore, the PTO/Na batteries could also retain a specific capacity of 201 mAh g À 1 after 300 cycles, confirming that DLCGPE achieves the purpose of inhibiting PTO dissolution and maintaining batteries stability. This work broadens the application of asymmetric electrolytes in organic secondary battery.