One-dimensional Ni3(hexahydroxytriphenylene)2 nanorods integrated with a biomass-derived carbon wood membrane cathode for efficient carbon dioxide conversion and long-cycle stability in lithium-carbon dioxide batteries

Lithium-carbon dioxide (Li-CO 2 ) batteries offer high theoretical energy density and significant potential for CO 2 utilization, yet their development is hindered by sluggish CO 2 reduction/evolution kinetics, large charge-discharge polarization, and the intrinsically poor electrical conductivity of the resulting Li 2 CO 3 discharge products. In this work, one dimensional conductive metal-organic framework, Ni 3 (hexahydroxytriphenylene) 2 (Ni 3 (HHTP) 2 ), are uniformly anchored onto a biomass-derived carbon wood (CW) membrane through a hydrothermal process to from a freestanding Ni 3 (HHTP) 2 @CW composite cathode. Benefiting from the synergistic integration of highly one dimensional conductive Ni 3 (HHTP) 2 nanorods and the hierarchical porous architecture of biomass-derived CW scaffold, the composite cathode provides abundant catalytic active sites and enables rapid electron/ion transport during electrochemical reactions. The Li-CO 2 battery employing Ni 3 (HHTP) 2 @CW cathode delivers an areal discharge capacity of 4.37 mAh cm −2 at 50 μA cm −2 with a low overpotential of 1.33 V, and demonstrates excellent cycling stability for over 800 cycles under a limited capacity of 100 μAh cm −2 at 100 μA cm −2 . In-situ XRD, in-situ EIS, and distribution of relaxation time analyses reveal enhanced charge-transfer kinetics and reversible formation/decomposition of Li 2 CO 3 on the composite cathode. This study provides a sustainable and effective strategy for designing low-cost, binder-free MOF/biomass-derived carbon composite cathodes for advanced Li-CO 2 energy storage systems.