Pseudocapacitive Anode Materials toward High-Power Sodium-Ion Capacitors

Sodium-ion storage technology holds great promise for large-scale, sustainable, and low-cost green energy storage systems. Overcoming the main limitations of sluggish Na+ diffusion kinetics and achieving high-power sodium-ion storage devices is critical but full of challenges. Recently, emerging pseudocapacitive sodium-ion storage materials are attracting attention due to their superior rate capability and other comprehensive electrochemical performance. Herein, this review covers the charge storage mechanism, features, and performance of pseudocapacitive sodium-ion storage anode materials and the assembled sodium-ion capacitors. The research processes of state-of-the-art pseudocapacitive sodium-ion storage anode materials, which display remarkable rate performance, high specific capacity and cycling stability, are introduced and discussed. Using the pseudocapacitive anode materials, advanced sodium-ion capacitors deliver high energy density at high power density. In the end, the outlooks of pseudocapacitive sodium-ion storage materials toward future high-power sodium-ion capacitors are briefly proposed.