Study on novel functional materials carboxymethyl cellulose lithium (CMC-Li) improve high-performance lithium-ion battery

• Novel functional material CMC-Li is synthesized with cotton as raw material by a unique two-step method.
• New nanometer fiber CMC-Li, CMC-Li/LFP, CLL models are obtained by electrospinning for the first time.
• Novel unique method of modified electrode materials using CMC-Li are applied in lithium-ion battery for the first time.
• The good electrochemical property using CMC-Li and new method for batteries is reported for the first time.
• This novel functional material and new method can increase the contents of freely moving lithium ions and the efficiency.

Novel cellulose derivative CMC-Li was synthesized by cotton as raw material. The mechanism of the CMC-Li modified electrode materials by electrospinning was reported. CMC-Li/lithium iron phosphate (LiFePO4, LFP) composite fiber coated with LFP and CMC-Li nanofibers was successfully obtained by electrospinning. Then, CMC-Li/LFP nano-composite fiber was carbonized under nitrogen at a high temperature formed CNF/LFP/Li (CLL) composite nanofibers as cathode material. It can increase the contents of Li+, and improving the diffusion efficiency and specific capacity. The battery with CLL as cathode material retained close to 100% of initial reversible capacity after 200 cycles at 168 mAh g−1, which was nearly the theoretical specific capacity of LFP. The cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and scanning electron microscope (SEM) were characterizing material performance. The batteries have good electrochemical property, outstanding pollution-free, excellent stability.