Ultrafast charging and ultralong cycle life in solid-state Al-ion batteries

Abstract

Designing and fabricating solid-state batteries with high-rate capability and long cycle life remains a feat. Here, for the first time, a free-standing gel polymer electrolyte (GPE) that exhibits an ultrahigh ionic conductivity of 1.29 × 10⁻² S cm⁻¹ is used to regulate the charge transfer between the GPE and Al electrode. Full batteries with a structure of Al/GPE/3D graphene are proved to be stable under current densities from 20 to 200 A g⁻¹, by providing a specific capacity of 122 mA h g⁻¹, a charging rate up to 1000 A g⁻¹ (0.24 s charging time), and a stability over 20 000 cycles. High-flux operations are found to be essential in lowering the energy request during high-rate reactions: not only reducing the surge voltage, but also increasing the energy (237 W h kg⁻¹@20 A g⁻¹) and power density (469 kW kg⁻¹@500 A g⁻¹) in output (>17%).