Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

A well-formulated electrolyte is proposed based on fluorinated carboxylate ester solvent, which showed a wide electrochemical window (0~4.73 V, vs. Li⁺/Li), low solvation energy (10.05 kJ mol^-1) and kept liquid...

Conventional intercalation compounds for lithium‐ion batteries (LIBs) suffer from rapid capacity fading and are even unable to charge–discharge with temperature decline, owing to the sluggish kinetics and solvation/desolvation process. In this work, a high‐performance rechargeable battery at ultralow temperature is developed by employing a nanosized Ni‐based Prussian blue (NiHCF) cathode. The battery delivers a high capacity retention of 89% (low temperature of −50 °C) and 82% (ultralow temperature of −70 °C) compared with that at +25 °C. Various characterizations and electrochemical investigations, including operando Fourier transform infrared spectra, in situ X‐ray diffraction, cyclic voltammetry response, and galvanostatic intermittent titration technique are carried out to detect the structural stability and electrochemical behavior at different temperatures. It turns out that the pseudocapacitive behavior drives the desolvation process at the interface, while fast diffusion in the bulk electrode accelerates the movement of Li + from the interface to the bulk materials. The unique synergistic features of intercalation pseudocapacitance at the electrolyte/electrode interface and high diffusion coefficient in the bulk electrode enables the NiHCF cathode with excellent low temperature performance. These findings offer a new direction for the design of LIBs operated at low temperature.

Lithium metal is an ideal anode for high‐energy rechargeable batteries at low temperature, yet hindered by the electrochemical instability with the electrolyte. Concentrated electrolytes can improve the oxidative/reductive stability, but encounter high viscosity. Herein, a co‐solvent formulation was designed to resolve the dilemma. By adding electrochemically “inert” dichloromethane (DCM) as a diluent in concentrated ethyl acetate (EA)‐based electrolyte, the co‐solvent electrolyte demonstrated a high ionic conductivity (0.6 mS cm−1), low viscosity (0.35 Pa s), and wide range of potential window (0–4.85 V) at −70 °C. Spectral characterizations and simulations show these unique properties are associated with the co‐solvation structure, in which high‐concentration clusters of salt in the EA solvent were surrounded by mobile DCM diluent. Overall, this novel electrolyte enabled rechargeable metallic Li battery with high energy (178 Wh kg−1) and power (2877 W kg−1) at −70 °C.

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Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Applying interlayers is the main strategy to address the large area specific resistance (ASR) of Li/garnet interface. However, studies on eliminating the Li2CO3 and LiOH interfacial lithiophobic contaminants are still insufficient. Here, thermal‐decomposition vapor deposition (TVD) of a carbon modification layer on Li6.75La3Zr1.75Ta0.25O12 (LLZTO) provides a contaminant‐free surface. Owing to the protection of the carbon layer, the air stability of LLZTO is also improved. Moreover, owing to the amorphous structure of the low graphitized carbon (LGC), instant lithiation is achieved, and the ASR of the Li/LLZTO interface is reduced to 9 Ω cm2. Lithium volatilization and Zr4+ reduction are also controllable during TVD. Compared with its high graphitized carbon counterpart (HGC), the LGC‐modified Li/LLZTO interface displays a higher critical current density of 1.2 mA cm−2, as well as moderate Li plating and stripping, which provides enhanced polarization voltage stability.