Li–CO2 batteries have received extensive attention due to their high energy storage capacity and utilization of CO2 resources. Herein, bimetallic MXene solid‐solution TiVC is prepared and combined with highly conductive graphene for the construction of binder‐free electrocatalyst cathodes for Li–CO2 batteries. Considering the electronic structure, the unique synergy effect between Ti and V in TiVC enhances the interfacial chemical bonding ability, facilitates sufficient exposure of active sites and promotes catalytic interfacial structural reformation, thereby promoting the reversible formation and decomposition of the chemically inert discharge product Li2CO3. Meanwhile, the abundant pores and excellent electron transfer ability of graphene aerogel are conducive to the gas diffusion and ion transport, thus reducing the mass and charge transfer resistance. As a result, the assembled Li–CO2 battery presents an excellent discharge capacity of 27 880 mAh g−1 with a stable discharge plateau of 2.77 V and low overpotential of 1.5 V based on the TiVC‐graphene aerogel electrocatalytic cathode. The density functional theory calculations are further performed to deeply reveal the unique electronic structure information between Ti and V in the solid‐solution TiVC. This study provides inspiration for exploring more bimetallic MXene solid solutions and developing advanced cathode catalysts for flexible Li–CO2 batteries.

Poly(ethylene oxide) (PEO) with excellent solvating capacity toward lithium salts and easy processable feature is considered as the promising polymer electrolyte matrix for energy storage devices. However, the poor capacity and cycling performances of PEO-based batteries resulted from weak mechanical strength and electrochemical properties greatly limit its development. Herein, chiral polyurethane (HPU) with a unique helical configuration is integrated into PEO, and a well-defined microphase separation architecture is induced in the resulted PEO@HPU hybrid. Besides the decreased crystallinity of PEO, the well-organized ordered and disordered microphase structure provides a "green channel" for Li + transfer, contributing to a record lithium ion transference number of 0.43 for PEO-based dual-ion conductors. The mechanical strength and dimensional stability of PEO are significantly improved by the introduction of rigid helical segments and intermolecular hydrogen bondings. The electrochemical window and the ionic conductivity of the PEO@HPU hybrid are 5.0 V (vs Li + /Li) and 4.92 × 10 −5 S cm −1 (60 °C), respectively. By synergism of the decreased crystallinity and microphase separation, the LiFePO 4 /Li cell assembled with the optimized PEO@HPU presents a high discharge capacity of 153 mA h g −1 at 0.1 C, and the capacity retention ratio is 83.6% after the 80th cycle with a Coulombic efficiency of approximately 99%. The growth of lithium dendrites is effectively inhibited, and the improved interfacial compatibility between PEO@HPU and the Li metal electrode also plays a crucial role. The introduction of a helical structure and the induced microphase separation may provide a new strategy for developing advanced solid-state polymer electrolytes for practical applications.

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Li-CO2 batteries have attracted close attention due to their ability to simultaneously store energy and capture CO2. The development of suitable catalytic cathodes plays a decisive role in promoting the...