Wood-improved cold-resistant all−in−one supercapacitor assembled from remodelable wood/PVA composite electrolytes

Cold−resistance CPEs were prepared with balsa wood skeleton and PVA/EG gel. • The CPEs showed a high ionic conductivity of 6.08 × 10 −3  S cm −1  at −30 °C. • Cold-resistant all−in−one SCs (ACS) have been prepared by remolding PVA gel. • Cold-resistant ACS showed specific capacitance of 284.8 mF cm −2  at −30 °C. All−in−one configuration and cold−resistance endow energy−storage devices with portability and the ability to work at low temperature but bring harsh electrolyte and electrode requirements. Compared to sandwich-like supercapacitors, all−in−one configured supercapacitors can significantly reduce electrode-electrolyte contact resistance, improve energy density, simplify the assembly process, effectively avoid multilayer structure slip under deformation, and lengthen service life. Herein, cold−resistance composite polymer electrolytes (CPEs) were prepared with chemically treated balsa wood skeleton and polyvinyl alcohol/ethylene glycol (PVA/EG) gel. The synergistic effects of wood and gel provide the CPEs with outstanding mechanical properties with high tensile strengths of up to 340 kPa. The microporous structure in the wood provides abundant ion transport channels, resulting in a high ionic conductivity of 6.08 × 10 −3  S cm −1 even at −30 °C. A series of cold-resistant all−in−one supercapacitors (ASC) have been prepared by remolding PVA gel, which reduced the electrolyte/electrode interfacial resistance, improved the portability and maintained a low temperature performance. The cold-resistant ACS showed outstanding performance, maintaining a small R s (42.1 Ω) and R ct (18.5 Ω) and high area specific capacitance (284.8 mF cm −2 ) at −30 °C. It is anticipated that cold−resistant, all−in−one supercapacitors based on wood/polymer complex electrolytes offer broad applications as energy storage devices. Download: Download high-res image (321KB) Download: Download full-size image