Electrothermally tailored lithiophilic Co/CoxOy@porous graphite composites for high-performance Li-ion/metal hybrid batteries

Abstract

Li-based batteries with high energy density and cyclic stability are essential for sustainable energy systems, whereas conventional design strategies are limited in restricted capacity and dendrite formation. Herein, we report precisely tunable Co/Co_xO_y@porous graphite (p-G) composites fabricated by the scalable electrothermal wave (ETW) process, enabling exceptional lithiophilic properties, increased surface area, and high porosity. The optimal heating-cooling rates adjusted by the ETW parameters could surpass the decomposition temperature of precursors yet suppress the excess thermal energy density inducing the aggregation of the resulting Co/Co_xO_y@p-G composite, thereby offering the rapid screening of their physicochemical characteristics. The screened Co/Co_xO_y@p-G composites as anodes in Li-ion/metal hybrid batteries, exhibit outstanding lithiation, Li plating at high capacities, and dendrite resistance. Compared to bare p-G anodes, they enhance Coulombic efficiency and cyclic stability by 600 % in half-cell tests, while maintaining an energy density ranging from 272.59 to 240.25 Wh∙kg^-1 over 110 cycles in full-cell tests, representing a 153.14 % improvement. The outcomes will inspire ultrafast yet effective fabrication strategies for high-performance electrochemical cells.