Structural composite batteries made from carbon fibre reinforced electrodes / polymer gel electrolyte prepregs

Full cells of structural composite batteries comprising carbon fibre reinforced anodes and cathodes decorated with lithium titanate and LiNi_0.3Mn_0.3Co_0.3O₂ (NMC111), respectively, embedded in a polymer gel electrolyte were produced. Spread carbon fibres were coated with cathode and anode active materials followed by impregnation with a polymer gel electrolyte consisting of PVDF particles dispersed in an ionic liquid containing a lithium salt. The resulting carbon fibre reinforced electrodes/polymer gel electrolyte prepregs could be easily stored, handled or, if needed, transported. Cathode and anode prepregs were laminated and fused by compression moulding, resulting within a time frame of couple of minutes in full cell structural composite batteries. The batteries were charged and discharged at current densities of 0.1C, resulting in a specific capacity of 35 mAh/g_NMC111 and energy density of 5.6 Wh/(kg battery). The composite batteries had a Young's modulus of 4.6 GPa and tensile strength of 32 MPa. A facile layup process enabled proof-of-concept demonstration of ‘all’ carbon fibre full cell multifunctional structural composite batteries.