Pretreatment of Graphite Anodes with Lithium Sulfate to Improve the Cycle Performance of Lithium‐Ion Batteries

Abstract

Graphite electrode surfaces are pretreated by spray‐deposition method with 0.5 mol L−1 Li2SO4 aqueous solution. The physical and electrochemical properties of a solid electrolyte interphase (SEI) film formed on the surface of Li2SO4‐treated graphite electrode are investigated by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and electrochemical measurements. The results show that the SEI film formed, promoted by Li2SO4, is thin, stable, effective, and elastic to accommodate volume changes of graphite electrode during electrochemical cycles. Due to the fact that the Li/mesophase carbon microbeads (MCMB) cell based on Li2SO4‐treated graphite electrode exhibits excellent cycling performance and low interfacial impedance, we can deduce that such modifies have positive implications for lithium‐ion batteries (LIBs), offering the possibility of faster‐charging LIBs and LIBs that are suitable for rate‐demanding applications, such electric vehicles and hybrid electric vehicles.

Detection of Over-Discharged Nickel Cobalt Aluminum Oxide Lithium Ion Cells Using Electrochemical Impedance Spectroscopy and Differential Voltage Analysis

“…4b and 4c, the SEI film resistance (R F ) and SEI film capacitance (C F ) at LCVs of 3.47, 3.00, and 2.50 V are identical; each R F gradually decreases up to 50 cycles and then remains constant in the following cycles, while C F gradually increases up to 50 cycles and then remains constant. These trends are similar to the results observed in our previous study where charge-discharge cycling was performed in the voltage ranges of 3.47-4.20 V and 3.47-4.40 V. 2 Cui et al 22 reported that an initial drop in R F is due to the continuous formation/modification of the primary rough SEI film. The SEI film is composed of organic and inorganic components.…”

Additive stabilization of SEI on graphite observed using cryo-electron microscopy

“…Reports show that Li 2 SO 4 -treated graphite exhibits outstanding cycling performance and low interfacial impedance. 9 Therefore, the formation of Li 2 SO 4 -dominating SEI using DTD is an effective method to improve the performance of graphite anode.…”

Lithium-ion battery cell formation: status and future directions towards a knowledge-based process design

“…Cui et al used a surface treatment of Gr with 0.5 mol L À1 Li 2 SO 4 aqueous solution, which resulted in the formation of thinner, more stable and elastic SEI layer capable of accommodating structural changes during cycling. 233 The study suggests that surface properties play an important role in the formation process. Further studies have found a correlation between Gr surface properties and first cycle specific charge loss, confirming the importance of the surface properties of active material.…”