New Desolvated Gel Electrolyte for Rechargeable Lithium Metal Sulfurized Polyacrylonitrile (S-PAN) Battery

作者:Wu Borong; Liu Qi; Mu Daobin*; Ren Yonghuan; Li Yu; Wang Lei; Xu Hongliang; Wu Feng
来源:Journal of Physical Chemistry C, 2014, 118(49): 28369-28376.
DOI:10.1021/jp507723n

摘要

A new desolvated gel electrolyte (DGE) is investigated for its use in lithium metal sulfurized polyacrylonitrile (S-PAN) battery. Lithium dendrite growth is examined under the DGE by scanning electron microscope (SEM). The electrolyte desolvation is analyzed with IR and H-1 NMR spectra as well as density functional theory (DFT) calculation using Gaussian09 package. The electrochemical performance of S-PAN cathode is compared under the DGE and a common electrolyte via galvanostatic charge/discharge. The growth mode of Li dendrite is schematically illustrated to elucidate the role of the DGE during the charge/discharge process. It is shown that the DGE can prevent the growth of dendrite from the Li anode surface. A specific capacity of 1276 mAh/g is retained under the DGE after 50 cycles at 60 mA/g current rate. It is indicated that the as-prepared gel electrolyte is desolvated, which is also confirmed with the theoretical calculation. The DGE weakens the solvation effect of the lithium ions and reduces the resistance of charge transfer at cathode/electrolyte interface; it increases lithium ion transference number as well, so enhancing the electrochemical performance of the cathode.