Phase change-mediated core-sheath 3D printing of hollow microlattice pseudocapacitive aerogel electrode with favorable electrochemical properties

Channel-interconnected regulation within 3D-printed pseudocapacitive electrode architecture to generate high active material loading/utilization and fast ion transport is pivotal but challenging for implementing high-performance pseudocapacitance system. Here we demonstrated for the first time the capability of an innovative phase change-mediated core-sheath DIW 3D printing for controllably constructing hollow-microlattice pseudocapacitive electrode with regular hollow channels in printed filaments and abundant well-interconnected hierarchical pores, which enabled fast substance diffusion/infiltration throughout entire thick filaments from both “interior-exterior” and “exterior-interior” directions for generating high-level yet effective loading of active materials as well as unimpeded ion transport, thereby boasting fast kinetics and remarkable capacitance of DIW-printed energy storage systems. [Display omitted] •Channel-interconnected pseudocapacitive electrode was constructed via phase change-mediated core-sheath DIW 3D printing.•Electrode featured regular hollow channels within printed filaments and abundant well-interconnected hierarchical pores.•Unique electrode structure enabled fast substance diffusion/infiltration throughout entire thick filament.•Assembled device exhibited fast kinetics and high capacitance. Channel-interconnected regulation within 3D-printed pseudocapacitive electrode architecture to generate high active material loading/utilization and fast ion transport is pivotal but challenging for implementing high-performance pseudocapacitance system. Herein, we demonstrated an innovative phase change-mediated core-sheath direct ink writing (DIW) 3D printing strategy for controllably constructing pseudocapacitive hollow-microlattice graphene/NiCo2O4 aerogel (HGNA) electrode, with regular hollow channels in printed filaments and abundant well-interconnected hierarchical pores built by jointing tortuous pseudocapacitive graphene nanosheets. The unique architectural features facilitated highly efficient diffusion and infiltration of substance throughout the entire thick filaments from both “interior-exterior” and “exterior-interior” directions, thereby enabling high-level yet effective loading of active materials as well as unimpeded ion transport across the printed bulk-structured electrode. Kinetics analysis revealed that the capacitance of pseudocapacitive HGNA electrode was primarily contributed from fast kinetic process. An asymmetric de