A zinc-conducting chalcogenide electrolyte

A solid-state zinc-ion battery can fundamentally eliminate dendrite formation and hydrogen evolution on the zinc anode from aqueous systems. However, enabling fast zinc ion + conduction in solid crystals is thought to be impossible. Here, we demonstrated a fluorine-doping approach to achieving fast Zn2+ transport in mesoporous ZnyS1-xFx. The substitutional doping of fluoride ion with sulfide substantially reduces Zn2+ migration barrier in a crystalline phase, while mesopore channels with bounded dimethylformamide enable nondestructive Zn2+ conduction along inner pore surface. This mesoporous conductor features a high room-temperature Zn2+ conductivity (0.66 millisiemens per centimeter, compared with 0.01 to 1 millisiemens per centimeter for lithium solidstate electrolyte) with a superior cycling performance (89.5% capacity retention over 5000 cycles) in a solid zincion battery and energy density (0.04 watt-hour per cubic centimeter) in a solid zinc-ion capacitor. The universality of this crystal engineering approach was also verified in other mesoporous zinc chalcogenide materials, which implies various types of potential Zn2+-conducting solid electrolytes.

Automated summary

A fluorine-doping approach was demonstrated to achieve fast Zn2+ transport in mesoporous ZnyS1-xFx, enabling solid-state zinc-ion batteries with high conductivity and cycling performance. The substitutional doping of fluoride ion with sulfide reduces Zn2+ migration barrier in a crystalline phase, while mesopore channels enable nondestructive Zn2+ conduction. This crystal engineering approach shows universality in other mesoporous zinc chalcogenide materials.