Valorizing Coal Tar: Macropore-Dominated RibbonNet-CoalCarb Boosts Charge Storage

Abstract

The practical application of quasi-solid-state microsupercapacitors (MSCs) is hampered by their low energy density. Designing a suitable structure of porous carbon for high-viscosity gel electrolytes is the key to boosting their energy storage capacity. In this work, we demonstrate macropore-dominated ribbon network coal-derived carbon (RNC) using heavy coal tar, a key byproduct of the coal chemical industry, as the precursor. The RNC’s macropore enables compatibility with gel electrolytes, resulting in an enhanced electrode/electrolyte interface and facilitating rapid electrolyte ion transport. RNC-based MSCs exhibit outstanding performance with 46.6 mF cm^–2 under 0.1 mA cm^–2, excellent rate capability, cycling durability, and mechanical flexibility. Integration into a wearable pressure sensing system as an independent power source further validates its practical application potential. This work is beneficial to the development of MSCs.