Lignin is an ideal carbon source because of its high carbon content and aromatic structure. The increasing awareness of sustainable development and environmental protection has promoted the interest in the application of renewable lignin biomass-derived carbon materials in the energy field. With the increasing demand for green high-performance energy storage materials, lignin carbon materials show great application prospects. In recent years, people have prepared a lot of carbon materials from lignin by different methods. However, the toughness of lignin-derived carbon nanofiber films and bio-carbon composite films is poor, which limits their application in high-performance flexible batteries.
To solve the above problems, the team of Academician Zhu Meifang of Donghua University proposed a simple method for large-scale synthesis of flexible CNT films from lignin: using floating catalytic chemical vapor deposition to synthesize CNT films with high toughness and electrical conductivity. Flexible CNT films can be used directly as electrodes, avoiding additional binders and conductive carbon, helping to increase the energy density of the battery. These properties make CNT films suitable for the manufacture of flexible body materials for Li-S batteries, while their high flexibility makes them ideal electrode materials for foldable soft-pack batteries. This work is one of the latest advances in the field of high-value conversion of renewable biomass by the team of Academician Meifang Zhu. In the past few years, in response to the national "two-carbon strategy" to improve the utilization of biomass resources, the team also proposed a new strategy to use FCCVD method to prepare biomass-derived carbon nanotube fibers. The tensile strength and conductivity of carbon nanotube fibers prepared by this method can reach 1.33GPa and 1.19 × 105 S m-1, respectively, which is higher than that of existing biomass derived carbon fibers (Nat. Commun., 2022, 13(1): This method can also be extended to other biomass (Green Energy & Environment, 2023, 8(6): 1711-1718.). In order to broaden the lignin processing method and reduce the use cost of carbon fiber, the team also developed low-cost, highly conductive lignin based carbon fiber felt that can be manufactured on a large scale by using melt blowing and carbonization technology processes, and used in the fields of sensors, catalytic materials and new energy (Int.J. Biol. Macromol., 2022). 216:388-396. Materials Horizons, 2023, DOI: 10.1039/D3MH01027A).