Entropy-driven disordered porous carbon (high entropy carbon) electrodes for high-performance supercapacitors

Abstract

Entropy is a very important state function in thermodynamics, and high-entropy materials have become a hot research field in recent years. Due to the adjustable category and concentration of active components, the high-entropy mixing state, and the synergistic effect of multiple elements, high-entropy materials can provide a variety of adsorption or reaction sites, so that high-entropy materials have been widely concerned in the field of electrochemistry. In this review, we try to summarize the design principle of disordered porous carbon from the perspective of entropy driving, and formally put forward a new concept of “high-entropy carbon materials”, and summarize three design principles of high-entropy carbon with “small graphene domain”: unit entropy, ring entropy and element entropy. The unit entropy increases the system entropy by decreasing the graphene domain size and increasing the number of basic units of the system (defining the "basic units" as "graphene domains"). The ring entropy is focused on the distortion of the graphene-plane six-membered carbon rings, resulting in asymmetric five/seven-membered carbon rings (5/7-membered carbon ring-based topological defects), so as to achieve the entropy increase. The element entropy is the goal of achieving high entropy by doping multiple non-metallic or metallic elements in the graphene lattice. We expect that establishing a link between entropy increase and capacitive performances will lead to novel capacitance storage mechanisms and new scientific perspectives.