Ultrahigh-energy and-power aqueous rechargeable zinc-ion microbatteries based on highly cation-compatible vanadium oxides

Aqueous multivalent-metal-ion intercalation chemistries hold genuine promise to develop safe and powerful microbatteries for potential use in many miniaturized electronics.However,their development is beset by state-of-the-art electrode materials having practical capacities far below their theoretical values.Here we demonstrate that high compatibility between layered transition-metal oxide hosts and hydrated cation guests substantially boost their multi-electron-redox reactions to offer higher capacities and rate capability,based on typical bipolar vanadium oxides preintercalated with hydrated cations(MVO).When seamlessly integrated on Au current microcollectors with a three-dimensional bicontinuous nanoporous architecture that offers high pathways of electron transfer and ion transport,the constituent ZnVOexhibits specific capacity of as high as ～527 mAh gat 5 mV sand retains ～300 mAh gat 200 mV sin 1 M ZnSOaqueous electrolyte,outperforming the MVO(M=Li,Na,K,Mg).This allows aqueous rechargeable zinc-ion microbatteries constructed with symmetric nanoporous ZnVO/Au interdigital microelectrodes as anode and cathode to show high-density energy of ～358 mWh cm(a value that is forty-fold higher than that of 4 V/500 μAh Li thin film battery) at high levels of power delivery.