Stretchable lithium batteries have attracted considerable attention as components in future electronic devices, such as wearable devices, sensors, and body-attachment healthcare devices. However, several challenges still exist in the bid to obtain excellent electrochemical properties for stretchable batteries. Here, a unique stretchable lithium full-cell battery is designed using 1D nanofiber active materials, stretchable gel polymer electrolyte, and wrinkle structure electrodes. A SnO2/C nanofiber anode and a LiFePO4/C nanofiber cathode introduce meso- and micropores for lithium-ion diffusion and electrolyte penetration. The stretchable full-cell consists of an elastic poly(dimethylsiloxane) (PDMS) wrapping film, SnO2/C and LiFePO4/C nanofiber electrodes with a wrinkle structure fixed on the PDMS wrapping film by an adhesive polymer, and a gel polymer electrolyte. The specific capacity of the stretchable full-battery is maintained at 128.3 mAh g-1 (capacity retention of 92%) even after a 30% strain, as compared with 136.8 mAh g-1 before strain. The energy densities are 458.8 Wh kg-1 in the released state and 423.4 Wh kg-1 in the stretched state (based on the electrode), respectively. The high capacity and stability in the stretched state demonstrate the potential of the stretchable battery to overcome its limitations.
Keywords: lithium‐ion batteries; nanofibers; stretchable batteries; stretchable gel polymer electrolytes; wrinkle structure.
© 2020 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.