Battery‐Type Electrode Materials for Sodium‐Ion Capacitors

Abstract Sodium‐ion capacitors (NICs), as a new type of hybrid energy storage devices, couples a high capacity bulk intercalation based battery‐style negative (or positive) electrode and a high rate surface adsorption based capacitor‐style positive (or negative) electrode, delivering high energy density, high power density, and long lifespan. Since the first NICs have been proposed in year 2012, numerous efforts have been put into searching for appropriate electrode materials to compose NICs devices with improved performance. Especially, battery‐type electrode materials carry greater responsibility on performance improvement of NICs. This review provides an overview of electrode materials for NICs according to energy storage mechanisms with an emphasis on battery‐type electrode materials design and improved NICs performance. Further, future challenges and perspectives of NICs are also discussed.