Fe metal‐organic framework/pyrolyzed bacterial cellulose composite as a high‐performance anode for lithium‐ion batteries

Summary In this research, Fe‐MOF (MIL‐53 [Fe]) was synthesized by solvothermal and applied as an anode of lithium‐ion batteries (LIBs). Carbonaceous material from pyrolyzed bacterial cellulose (pBC) was incorporated in the solvothermal synthesis of MIL‐53(Fe) to improve its morphology and electrochemical properties. The MIL‐53(Fe) with pBC addition (MIL‐53(Fe)@pBC) exhibited reduced particle size and size distribution, larger surface area and pore volume, and modified crystal shape and interior structure. The incorporation also altered the functional group of the dicarboxylic ligand and formed a thin carbon layer coating which enhanced electrical conductivity significantly. The refined microstructure of the MIL‐53(Fe)@pBC compared to the pure MIL‐53(Fe) was proved to enhance the electrochemical activities of the LIB cells. The specific capacity, rate capability, and cyclic performance were boosted with pBC addition due to the increased ion diffusion kinetics in the lithiation/delithiation process. Interestingly, the MIL‐53(Fe)@pBC anode showed a peculiar increase in the reversible capacity with LIB cycles after the initial capacity fading. The analysis after the 100th cycle suggested that the lithiation/delithiation process was mediated by phase transformation through the Li+ storage mechanism. This work has shown that the MIL‐53(Fe)@pBC is an excellent candidate for anode materials in LIBs with high efficiency at long life cycles. Carbon from pyrolyzed bacterial cellulose (pBC) was incorporated into the Fe metal‐organic framework (MIL‐53(Fe)) to improve its morphology and electrochemical properties. Lithium‐ion batteries, using an anode from the synthesized composite material (MIL‐53(Fe)@pBC), showed enhanced specific capacity, rate capability, and cyclic performance.