Electrochemical Deposition and Dissolution of Lithium on a Carbon Fiber Composite Electrode in a Solvate Ionic Liquid

Abstract

Electrochemical deposition and dissolution of Li metal on a carbon fiber composite electrode were investigated in lithium bis(trifluoromethylsulfonyl)amide-tetraglyme solvate ionic liquid electrolyte. The carbon fiber composite coated on a Cu substrate was composed of vapor-grown carbon fiber (VGCF ® -H) and poly(vinylidene fluoride). The coulombic efficiency for dissolution of Li deposits on the VGCF ® -H modified Cu electrode was kept more than 98% at 100th cycle and higher than that on a Cu electrode in the solvate ionic liquid. Li was deposited in the porous structure of the VGCF ® -H modified Cu electrode and scarcely observed on the surface of the VGCF ® -H modified Cu probably because the overpotential for the reduction of Li is smaller on the Cu substrate and/or deposited Li than that on the cylindrical basal plane of VGCF ® -H. This result suggests that the voids in the carbon fiber network effectively act as the Li deposition sites at the electrode|separator interface in the coin cell.

Characterization of the Solid-Electrolyte Interphase between a Cu Electrode and LiN(CF3SO2)2-triglyme Solvate Ionic Liquid

“…We have reported the improvement of the coulombic efficiency for deposition and dissolution of Li in the [Li (G4)]TFSA SIL using a carbon fiber-modified Cu substrate, although the internal short circuit due to the whisker-like growth of Li deposits was observed on a bare Cu substrate. 11 The whiskerlike growth of Li may lower the coulombic efficiency due to the detachment of Li from the current collector during dissolution. The control of the morphology of Li deposits has been investigated in conventional organic electrolytes and ionic liquids for decades.…”

Effect of Temperature on Li Electrodeposition Behavior in Room-Temperature Ionic Liquids Comprising Quaternary Ammonium Cation

“…[3][4][5][6][7][8][9][10][11][12][13] Many researchers have studied the mechanism of Li dendrite formation and how to suppress it. Surface film control, [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] alloy formation, 35,36 addition of inhibitors, [37][38][39] introduction of special structures in separators, [40][41][42][43][44][45] and use of well-designed current collectors [46][47][48][49] and well-patterned Li surface [50][51][52][53] have been reported as techniques for suppressing dendrite formation. Despite the abundance of methods for dendrite suppression, the origin of dendrite formation is yet to be elucidated.…”

Bending Anchoring Reinforcement of Zinc Nanosheets for Carbon Fiber Composites

“…The electrophoretic deposition (EPD) of metal nanomaterials on the surface of carbon fiber can improve the surface energy of carbon fiber and then improve the wettability and binding ability of carbon fiber to resin and enhance the performance of carbon fiber/epoxy composite. [20][21][22][23] Due to the conductive properties of carbon fibers, EPD can be used to deposit any powder solid, including particles and nanoparticles, on the surface of carbon fibers in the form of electrophoresis. In the electrodeposition method, metal deposition is the most convenient, and the effect is better.…”