Improved performance of structural battery composites through carbon fiber electrode/current collector integration

Carbon fibers (CF) reinforced structural battery composites (SBCs) using single CF current collectors (SCF) are proposed to enhance mechanical and electrochemical properties over traditional metal/CF assembly current collectors (M/CF). This study fabricates SBCs using LiFePO₄ (LFP)-coated CF fabric as the cathode, graphite-coated CF fabric as the anode, and a porous resin soaked with liquid electrolyte as the structural electrolyte. SCF-SBCs exhibit an initial specific capacity of 122.0 mAh/g_LFP (43.6 mAh/g_electrode) at 0.3C, which is 52.3 % higher than that of the M/CF-SBCs, with an initial energy density of 10.0 Wh/kg. After 100 cycles, SCF-SBCs maintain 91.9 % of their capacity, in contrast to 72.5 % for MCF-SBCs. Furthermore, SCF-SBCs demonstrate superior tensile and flexural strengths of 221.8 MPa and 119.8 MPa, respectively, which are 127.0 % and 59.3 % higher than those of MCF-SBCs. Overall, the notable benefits of SCF-SBCs in electrochemical and mechanical aspects are confirmed.