Boosting the Zn storage capacity of MoO nanoribbons by modulating the electrons spin states of Mo via Ni doping.

Aqueous zinc-ion batteries (AZIBs) have received considerable potential for their affordability and high reliability. Among potential cathodes, α-MoO stands out due to its layered structure aligned with the (010) plane, offering extensive ionic insertion channels for enhanced charge storage. However, its limited electrochemical activity and poor Zn transport kinetics present significant challenges for its deployment in energy storage devices. To overcome these limitations, we introduce a new strategy by doping α-MoO with Ni (Ni-MoO), tuning the electron spin states of Mo. Thus modification can activate the reactivity of Ni-MoO towards Zn storage and weaken the interaction between Ni-MoO and intercalated Zn, thereby accelerating the Zn transport and storage. Consequently, the electrochemical properties of Ni-MoO significantly surpass those of pure MoO, demonstrating a specific capacity of 258 mAh g at 1 A g and outstanding rate performance (120 mAh g at 10 A g). After 1000 cycles at 8 A g, it retains 76 % of the initial capacity, with an energy density of 154.4 Wh kg and a power density of 11.2 kW kg. This work proves that the modulation of electron spin states in cathode materials via metal ion doping can effectively boost their capacity and cycling durability.