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High‐voltage lithium metal batteries are the most promising energy storage technology due to their excellent energy density (>400 Wh kg−1). However, the oxidation decomposition of conventional carbonate‐based electrolytes at the high‐potential cathode, the detrimental reaction between the lithium anode and electrolyte, particularly the uncontrolled lithium dendrite growth, always lead to a severe capacity decay and/or flammable safety issues, hindering their practical applications. Herein, a solvation structure engineering strategy based on tuning intermolecular interactions is proposed as a strategy to design a novel nonflammable fluorinated electrolyte. Using this approach, this work shows superior cycling stability in a wide temperature range (−40 °C to 60 °C) for a 4.4 V‐class LiNi0.8Co0.1Mn0.1O2 (NCM811)‐based Li‐metal battery. By coupling the high‐loading of NCM811 cathode (3.0 mAh cm−2) and a controlled amount of lithium anode (twofold excess of Li deposition on Cu, Cu@Li) (N/P = 2), the Cu@Li || NCM811 full cell can cycle more than 162 cycles with high‐capacity retention of 80%. This work finds that the change of the coordination environment of Li+ with solvent and PF6− by tuning intermolecular interaction is an effective method to stabilize the electrolyte and electrode performance. These discoveries can provide a pathway for electrolyte design in metal ion batteries. [ABSTRACT FROM AUTHOR]

Aqueous ammonium ion battery is a promising sustainable energy storage system. However, the side reactions originating from electrolytes (the water decomposition and host material dissolution) preclude its practical applications. Unlike the metal‐based aqueous batteries, the idea of "ultrahigh concentrated electrolyte" is not feasible due to the strong hydrolysis of ammonium ions. Therefore, we propose an effective and sustainable strategy for the water hydrogen bond network modulation by adding sucrose into the electrolytes. The sucrose can form sucrose‐water hydrogen bond networks to break the continuous water hydrogen bond network, thereby inhibiting water decomposition significantly. Moreover, the weak hydrogen bond interaction between ammonium and sucrose facilitates rapid ion migration, leading to an improved ionic conductivity. This work presents a new electrolyte modulating strategy for the practical application of aqueous ammonium ion batteries. [ABSTRACT FROM AUTHOR]

In addressing the global climate crisis, the energy storage performance of Li‐ion batteries (LIBs) under extreme conditions, particularly for high‐energy‐density Li‐rich layered oxide (LRLO) cathode, is of the essence. Despite numerous researches into the mechanisms and optimization of LRLO cathodes under ideal moderate environment, there is a dearth of case studies on their practical/harsh working environments (e.g., pouch‐type full‐cell, high‐temperature storage), which is a critical aspect for the safety and commercial application. In this study, using pouch‐type full‐cells as prototype investigation target, the study finds the cell assembled with LRLO cathode present severer voltage decay than typical NCM layered cathode after high‐temperature storage. Further decoupling elucidates the primary failure mechanism is the over‐activation of lattice oxidized oxygen (aggravate by high‐temperature storage) and subsequent escape of oxidized oxygen species (On−), which disrupts transition metal (TM) coordination and exacerbates electrolyte decomposition, leading to severe TM dissolution, interfacial film reconstruction, and harmful shuttle effects. These chain behaviors upon high‐temperature storage significantly influence the stability of both electrodes, causing substantial voltage decay and lithium loss, which accelerates full‐cell failure. Although the anionic redox reaction can bring additional energy, but the escape of metastable On− species would introduce new concerns in practical cell working conditions. [ABSTRACT FROM AUTHOR]