Biomass-based phase change material gels demonstrating solar-thermal conversion and thermal energy storage for thermoelectric power generation and personal thermal management

•A ternary PCMGs consisting of octadecanol, SEBS and hydroxylated carbon nanotubes are proposed.•PCMGs present excellent flexibility, improved form-stability and high biocompatibility.•PCMGs possess high thermal energy storage capacity, high solar absorbance and high cost-effectiveness.•PCMGs are utilized for thermoelectric power generation and personal thermal management.