Functional carbon materials for high-performance Zn metal anodes

The realization of "carbon peak" and "carbon neutralization" highly depends on the efficient utilization of renewable energy sources. Exploring reliable and low-cost electrochemical energy storage systems is an ever-growing demand for renewable energy integration. Among available candidates, aqueous zinc-ion batteries (AZIBs) receive extensive researchers' attention because of their material abundance, high capacity, high safety, and environmental friendliness. However, the irreversible issues of Zn anode in terms of notorious dendric Zn growth, Zn corrosion/hydrogen evolution, and passivation significantly impede the commercialization of high-performance AZIBs. Carbon materials have advantages of large specific surface area, low cost, high electrical conductivity, controllable structure, and good stability. Their application provides remedies for improving the comprehensive performance of Zn anodes. In this review, the fundamentals and issues of Zn anodes, and the research progress with functional carbon materials for Zn anodes in recent years are presented. Three major strategies are described in detail, including the use of carbon materials (carbon nanotubes, graphene, carbon fiber, metal-organic framework (MOF) derived host, etc.) as Zn plating/stripping substrates, as protective coating layers on Zn, and as electrolyte additives. Finally, the remaining challenges and perspectives of carbon materials in high-performance AZIBs are outlined.