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

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 x 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%).

Automated summary

This study successfully designs and fabricates solid-state batteries with high-rate capability and long cycle life using a gel polymer electrolyte with ultrahigh ionic conductivity. The full batteries with the Al/GPE/3D graphene structure exhibit stability, high specific capacity, charging rate, and cycling stability under high current densities. Furthermore, high-flux operations play an important role in reducing energy demand during high-rate reactions.