Advances and challenges in zinc-ion hybrid supercapacitors: insights into cathode and anode material development

Zinc-ion hybrid supercapacitor (ZIHSC) is one of the popular emerging battery hybrid supercapacitors which integrates Zinc-ion battery electrode with capacitive electrode, thereby, taking advantages of high energy and power densities in addition to cycle stability. Their easy availability, optimum stability, high volumetric capacity and safety efficacy make ZIHSC a favoured choice over other battery hybrid supercapacitor. The research progress on ZIHSC is still in the bud stage and mainly faces challenges in developing a high energy density cathode and dendrite-free anode which hinder its practical applicability. To tackle these issues there must a proper understanding of the Zn²⁺ ion’s charge storage mechanism for the synthesised electrode materials which would be helpful in developing a technologically efficient ZIHSC. This review provides an overview of the fundamental working and performance metrics of ZIHSC. It then discusses about the different cathode and anode materials in length. This review work also highlights some of the newly developed electrode materials’ effectiveness in enhancing the ZIHSC’s performance. The challenges and the solutions associated with cathode and anode were also addressed in this review.