Study on Effects of Carboxymethyl Cellulose Lithium (CMC-Li) Synthesis and Electrospinning

Study on Effects of Carboxymethyl Cellulose Lithium (CMC-Li) Synthesis and Electrospinning for High-Rate Lithium-Ion Battery

Lei Qiu, Ziqiang Shao , Mingshan Yang, Wenjun Wang, Feijun Wang, Junling Wan, Jianquan Wang, Jia Li, Hongtao Duan

Battery with CMC-Li for binder has the advantages of higher discharge capacity,cycle performance.

Figure captions

Fig.1. The preliminary investigation of the mechanism of the CMC-Li binder.

Hydrophilic CMC-Li binder that has special structure for application in battery mechanism has study for the first time.

Fig.2. Synthesis and characterization of CMC-Li.

CMC-Li that was suitable for application in battery was synthesized by two steps. By the analysis of IR spectrogram, it also confirmed the formation of the intermediate products of CMC, CMC-H and last products CMC-Li.

Fig.3.The 1H-NMR spectrums of CMC-Li.

By the analysis of 1H-NMR spectrogram, it also confirmed the formation of the intermediateproducts of CMC-Li.

Fig.4.SEM photos at two different the mass ratio of water: tetrahydrofuran solvents of electrospinning CMC-Li nanofibers.The new cellulose derivatives CMC-Li was successfully electrospun for the first time by using mixed solvents. The mass ratio of solvent water: tetrahydrofuran was9:1, 8:2,7:3 and 6:4, when other spinning conditions remained unchanged.

Fig.5.SEM photos of composite fibers before and after carbonization.

Preparation AQ/CMC-Li, AQ/CNF/Li nanometer composite fiber, and AQ particles were equably dispersed in the fiber matrix after carbonization, and then formed the compound coating material of AQ/CNF/Li. Enhance conductivity and battery performance.

Fig.6.The complex materials are characterized with the help of analysis of TG for binders.

The scans of thermal stability of different binders measured by TG, CMC-Lis were more easily decomposed at the end of its battery life than PVDF, PVDF shows a decomposition temperature of approximately 450 oC, and CMC-Li shows exactly the same decomposition pattern of 270oC. They are completely suitable for application in lithium ion battery.

Fig.7.The CV curves of AQ electrodes with different binders.

The CV curves of AQ electrodes prepared using the water-based adhesive are sharper than those prepared using the PVDF binder. The distance between the discharge and charge curves of CMC-Li/AQ is smaller than that of PVDF/AQ, which shows that the polarization of the former is weaker than the latter.

Fig.8.The charge-discharge curve of different binder electrodes.

The first discharge specific capacity of the CMC-Li / AQ electrode is higher than a PVDF/AQ electrode at a current density of 0.2 mA. cm−2.

Fig.9. The cycle life curve of the AQ electrode with different binders

Water-based binder for AQ electrode material showed improved performance, and the cycle stabilities of various water-based binderswere different.

Fig.10. Impedance responses of electrodes with different binders.The results indicated that the interfacial properties between AQ electrodeand electrolyte were improved by the use of CMC-Li to increase the electrochemical reaction and dynamics performance.