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Highlights: A class of solvent-free covalent organic framework (COF) single-ion conductors (Li-COF@P) has been designed via ion–dipole interaction as opposed to traditional ion–ion interaction, promoting ion dissociation and Li+ migration through directional ionic channels. The Li-COF@P enabled long cycle life (88.3% after 2000 cycles) in all-solid-state Li organic batteries (ASSLOBs) under ambient operating conditions, which outperformed those of previously reported ASSOLBs. This Li-COF@P strategy holds promise as a viable alternative to the currently prevalent inorganic solid electrolytes. Single-ion conductors based on covalent organic frameworks (COFs) have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical versatility. However, the sluggish Li+ conduction has hindered their practical applications. Here, we present a class of solvent-free COF single-ion conductors (Li-COF@P) based on weak ion–dipole interaction as opposed to traditional strong ion–ion interaction. The ion (Li+ from the COF)–dipole (oxygen from poly(ethylene glycol) diacrylate embedded in the COF pores) interaction in the Li-COF@P promotes ion dissociation and Li+ migration via directional ionic channels. Driven by this single-ion transport behavior, the Li-COF@P enables reversible Li plating/stripping on Li-metal electrodes and stable cycling performance (88.3% after 2000 cycles) in organic batteries (Li metal anode||5,5'-dimethyl-2,2'-bis-p-benzoquinone (Me2BBQ) cathode) under ambient operating conditions, highlighting the electrochemical viability of the Li-COF@P for all-solid-state organic batteries. [ABSTRACT FROM AUTHOR]

Rechargeable batteries, typically represented by lithium-ion batteries, have taken a huge leap in energy density over the last two decades. However, they still face material/chemical challenges in ensuring safety and long service life at temperatures beyond the optimum range, primarily due to the chemical/electrochemical instabilities of conventional liquid electrolytes against aggressive electrode reactions and temperature variation. In this regard, a gel polymer electrolyte (GPE) with its liquid components immobilized and stabilized by a solid matrix, capable of retaining almost all the advantageous natures of the liquid electrolytes and circumventing the interfacial issues that exist in the all-solid-state electrolytes, is of great significance to realize rechargeable batteries with extended working temperature range. We begin this review with the main challenges faced in the development of GPEs, based on extensive literature research and our practical experience. Then, a significant section is dedicated to the requirements and design principles of GPEs for wide-temperature applications, with special attention paid to the feasibility, cost, and environmental impact. Next, the research progress of GPEs is thoroughly reviewed according to the strategies applied. In the end, we outline some prospects of GPEs related to innovations in material sciences, advanced characterizations, artificial intelligence, and environmental impact analysis, hoping to spark new research activities that ultimately bring us a step closer to realizing wide-temperature rechargeable batteries. [ABSTRACT FROM AUTHOR]

Despite the enormous efforts to control the growth behavior of Li, achieving a dendrite‐free Li deposition and high‐energy‐density have remained an inevitable challenge of Li metal batteries. Here, the conformal deposition of Li metal is reported on electroactive organic materials to achieve a high‐energy‐density and electrochemical longevity. To this end, Li2C8H4O4 (Li2TP), which can act as both the electrode material (providing the redox capacity) and Li host (inducing the dendrite‐free Li deposition), is used as the model electroactive organic material. The Li2TP host exhibits reversible sequential lithiation/delithiation and Li deposition/stripping reactions. Consequently, a Li‐free full cell constructed by the Li2TP host (without pre‐charging) and a LiFePO4 cathode delivered a high areal capacity (≈3.8 mAh cm−2), exceptional rate performance (≤12 mA cm−2), and superior cyclability (80% capacity retention after 100 cycles). This electroactive organic material‐based Li host strategy can provide a new perspective for the development of practical Li metal batteries. [ABSTRACT FROM AUTHOR]

Current state‐of‐the‐art Li batteries use single‐phase electrolytes; however, these electrolytes often encounter difficulty in simultaneously fulfilling the nonidentical electrochemical requirements of cathodes and anodes. Here, a class of immiscible binary liquid electrolyte (BLE) is designed by starving free solvent molecules. Based on their electrochemical stability window, 1,2‐dimethoxyethane (DME) and succinonitrile (SN) are selected as model solvents for Li‐metal anodes and LiNi0.8Co0.1Mn0.1 (NCM811) cathodes, respectively. Li bis(fluorosulfonyl)imide (LiFSI), which promotes Li+ solvation (i.e., reduces free solvents), enables the phase separation of the miscible solvent mixture (SN−DME), and an increase in its concentration strengthens the coordination of Li+−FSI− in the solvation sheath, thus yielding (anion‐derived) fluorine‐rich electrode–electrolyte interphases. The resulting BLE allows 4.4 V Li‐metal full cells to exhibit a stable capacity retention under a constrained cell condition (Li (20 µm, 4.1 mAh cm−2)||NCM811 (3.8 mAh cm−2), N (negative)/P (positive) capacity ratio = 1.08), which exceed those of previously reported binary liquid electrolytes. [ABSTRACT FROM AUTHOR]

Challenges facing high‐voltage/high‐capacity cathodes, in addition to the longstanding problems pertinent to lithium (Li)‐metal anodes, should be addressed to develop high‐energy‐density Li‐metal batteries. This issue mostly stems from interfacial instability between electrodes and electrolytes. Conventional carbonate‐ or ether‐based liquid electrolytes suffer from not only volatility and flammability but also limited electrochemical stability window. Here, we report a nitrile electrolyte strategy based on concentrated nitrile electrolytes (CNEs) with co‐additives. The CNE consists of high‐concentration lithium bis(fluorosulfonyl)imide (LiFSI) in a solvent mixture of succinonitrile (SN)/acetonitrile (AN). The SN/AN solvent mixture is designed to ensure high oxidation stability along with thermal stability, which are prerequisites for high‐voltage Li‐metal cells. The CNE exhibits interfacial stability with Li metals due to the coordinated solvation structure. Lithium nitrate (LiNO3) and indium fluoride (InF3) are incorporated in the CNE as synergistic co‐additives to further stabilize solid‐electrolyte interphase (SEI) on Li metals. The resulting electrolyte (CNE + LiNO3/InF3) enables stable cycling performance in Li||LiNi0.8Co0.1Mn0.1 and 4.9 V‐class Li||LiNi0.5Mn1.5O4 cells. Notably, the Li||LiNi0.5Mn1.5O4 cell maintains its electrochemical activity at high temperature (100 °C) and even in flame without fire or explosion. [ABSTRACT FROM AUTHOR]