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Abstract The concept of employing highly concentrated electrolytes has been widely incorporated into electrolyte design, due to their enhanced Li‐metal passivation and oxidative stability compared to their diluted counterparts. However, issues such as high viscosity and sub‐optimal wettability, compromise their suitability for commercialization. In this study, we present a highly concentrated dimethyl ether‐based electrolyte that appears as a liquid phase at ambient conditions via Li⁺‐ solvents ion‐dipole interactions (Coulombic condensation). Unlike conventional high salt concentration ether‐based electrolytes, it demonstrates enhanced transport properties and fluidity. The anion‐rich solvation structure also contributes to the formation of a LiF‐rich salt‐derived solid electrolyte interphase, facilitating stable Li metal cycling for over 1000 cycles at 0.5 mA cm⁻², 1 mAh cm⁻²condition. When combined with a sulfurized polyacrylonitrile (SPAN) electrode, the electrolyte effectively reduces the polysulfide shuttling effect and ensures stable performance across a range of charging currents, up to 6 mA cm⁻². This research underscores a promising strategy for developing an anion‐rich, high concentration ether electrolyte with decreased viscosity, which supports a Li metal anode with exceptional temperature durability and rapid charging capabilities. 

All-climate temperature operation capability and increased energy density have been recognized as two crucial targets, but they are rarely achieved together in rechargeable lithium (Li) batteries. Herein, we demonstrate an electrolyte system by using monodentate dibutyl ether with both low melting and high boiling points as the sole solvent. Its weak solvation endows an aggregate solvation structure and low solubility toward polysulfide species in a relatively low electrolyte concentration (2 mol L −1 ). These features were found to be vital in avoiding dendrite growth and enabling Li metal Coulombic efficiencies of 99.0%, 98.2%, and 98.7% at 23 °C, −40 °C, and 50 °C, respectively. Pouch cells employing thin Li metal (50 μm) and high-loading sulfurized polyacrylonitrile (3.3 mAh cm −2 ) cathodes (negative-to-positive capacity ratio = 2) output 87.5% and 115.9% of their room temperature capacity at −40 °C and 50 °C, respectively. This work provides solvent-based design criteria for a wide temperature range Li-sulfur pouch cells. 

Lithium metal batteries are capable of pushing cell energy densities beyond what is currently achievable with commercial Li-ion cells and are the ideal technology for supplying power to electronic devices at low temperatures (≤−20 °C). To minimize the thermal management requirements of these devices, batteries capable of both charging and discharging at these temperatures are highly desirable. Here, we report >4 V Li metal full cell batteries (N/P = 2) capable of hundreds of stable cycles down to −40 °C, unambiguously enabled by the introduction of cation/anion pairs in the electrolyte. Via controlled experimental and computational investigations in electrolytes employing 1,2-dimethoxyethane as the solvating solvent, we observed distinct performance transitions in low temperature electrochemical performance, coincident with a shift in the Li + binding environment. The performance advantages of heavily ion-paired electrolytes were found to apply to both the cathode and anode, providing Li metal Coulombic efficiencies of 98.9, 98.5, and 96.9% at −20, −40, and −60 °C, respectively, while improving the oxidative stability in support of >4 V cathodes. This work reveals a strong correlation between ion-pairing and low-temperature performance while providing a viable route to Li metal full batteries cycling under extreme conditions. 

Abstract A low‐carbon future demands more affordable batteries utilizing abundant elements with sustainable end‐of‐life battery management. Despite the economic and environmental advantages of Li‐MnO₂batteries, their application so far has been largely constrained to primary batteries. Here, we demonstrate that one of the major limiting factors preventing the stable cycling of Li‐MnO₂batteries, Mn dissolution, can be effectively mitigated by employing a common ether electrolyte, 1 mol/L lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in 1,3‐dioxane (DOL)/1,2‐dimethoxyethane (DME). We discover that the suppression of this dissolution enables highly reversible cycling of the MnO₂cathode regardless of the synthesized phase and morphology. Moreover, we find that both the LiPF₆salt and carbonate solvents present in conventional electrolytes are responsible for previous cycling challenges. The ether electrolyte, paired with MnO₂cathodes is able to demonstrate stable cycling performance at various rates, even at elevated temperature such as 60°C. Our discovery not only represents a defining step in Li‐MnO₂batteries with extended life but provides design criteria of electrolytes for vast manganese‐based cathodes in rechargeable batteries. 

Abstract Achieving increased energy density under extreme operating conditions remains a major challenge in rechargeable batteries. Herein, we demonstrate an all‐fluorinated ester‐based electrolyte comprising partially fluorinated carboxylate and carbonate esters. This electrolyte exhibits temperature‐resilient physicochemical properties and moderate ion‐paired solvation, leading to a half solvent‐separated and half contact‐ion pair in a sole electrolyte. As a result, facile desolvation and preferential reduction of anions/fluorinated co‐solvents for LiF‐dominated interphases are achieved without compromising ionic conductivity (>1 mS cm⁻¹even at −40 °C). These advantageous features were found to apply to both lithium metal and sulfur‐based electrodes even under extreme operating conditions, allowing stable cycling of Li || sulfurized polyacrylonitrile (SPAN) full cells with high SPAN loading (>3.5 mAh cm⁻²) and thin Li anode (50 μm) at −40, 23 and 50 °C. This work offers a promising path for designing temperature‐resilient electrolytes to support high energy density Li metal batteries operating in extreme conditions.