A review on recent developments and challenges of cathode materials for rechargeable aqueous Zn-ion batteries

Owing to their high cost and safety hazards, and the low abundance of Li in natural resources, the future of Li-ion batteries is becoming difficult. To replace Li-ion batteries, aqueous multivalent ion batteries are considered to be a worthwhile choice. In particular, aqueous zinc ion batteries are becoming an attractive option due to the natural abundance and unique properties of zinc. However, as for the Li-ion battery, the Zn-ion battery also has its own inadequacies in terms of cathodes. Finding a suitable cathode material for Zn-ion batteries with adequate structural stability and high capacity is an uphill task for researchers. This review presents the recent developments of various cathode materials in zinc ion batteries and their effectiveness towards the advancement of Zn-ion batteries. Based on the collected literature, various strategies adopted for enhancing the performance of Zn-ion batteries are also briefly discussed in this review. Furthermore, the explicit progress and future perspectives of Zn-ion batteries are also discussed.