Hierarchical Microchannel Carbons Derived from Biological Phloem Tissues as High-Performance Anode for Lithium-Ion Batteries

Abstract

With the upgrading of consumption, the existing carbon-based anode materials are facing the major challenges of high preparation cost and low initial Coulomb efficiency. The fast-growing and developed sieve tube network is an inspiration to transform cattail phloem tissue (CPT) into a high-performance carbon-based anode for lithium-ion battery. In this study, porous carbon materials from CPT with abundant microchannel and nanochannel were prepared by a top-down strategy combined with an indispensable passivation process. The sidewall and end of the sieve tube are fully covered by a large number of pore structures and various supporting cells, thus ensuring the stiffness and tensile strength of phloem tissue. And benefiting from the neoteric hierarchical porous structure without Li+ trapping sites, the cells with CPT anode showed high electrochemical performance. For the passivated CPT electrode, the reversible capacity increased to 321.6 mAh/g, and the initial Coulomb efficiency was 1.47 times higher than that of the passivated CPT electrode. The CPT exhibits excellent rate performance under high current, which indicates that the abundant pore structure on the surface of the sieve tube is an effective measure to improve ion diffusion. Besides, the generation mechanism of high-performance CPT is analyzed through microstructure characterization. The improvement of electrochemical performance of CPT in this work has provided a clear strategy for the application of resource-rich natural biomass to electrochemical products.