Computational Study on the Effects of Mechanical Constraint on the Performance of Si Nanosheets as Anode Materials for Lithium-Ion Batteries

Abstract

Lithiation process of Si has been widely studied, while most of the previous works neglected the effects of mechanical constraint from the accessory materials such as binder and conductive additive on Si. In this paper, we carry out molecular dynamics simulations to investigate the effects of mechanical constraint on the performances, such as capacity and lithiation rate, of Si nanosheets as the anode material for lithium-ion batteries. Our results show that strong mechanical constraint would largely affect the capacity and lithiation rate of Si nanosheets. Remedial strategies for improving the capacity and lithiation rate of the constrained Si nanosheets are proposed, giving rise to guidelines for the design of Si-based anode material for high-performance lithium-ion batteries.

Thickness gradient promotes the performance of Si-based anode material for lithium-ion battery

“…Taking 𝐸 e = 19.7 GPa [48], 𝜈 e = 0.3 (assumed), 𝐸 c = 128 GPa , 𝜈 c = 0.33 [49], 𝑡 c = 10 μm, 𝑅 = 7.5 mm in Eq. ( 1), the cross-sectional profile of the optimal thickness 𝑡 e (𝑟) is plotted in Fig.…”

Insights into the Interfacial Instability between Carbon-Coated SiO Anode and Electrolyte in Lithium-Ion Batteries

“…Lithium-ion batteries (LIBs) based on graphite anode have been extensively used in our life from portable electronic devices to electric vehicles, but there is always a persistent need for higher energy densities of LIBs. − Silicon (Si) presents the most promising alternative to graphite anode with much higher theoretical specific capacity (3579 mAh g –1 as compared with 372 mAh g –1 of graphite). ,, However, the application of neat Si is prohibited by its drastic volume fluctuation (∼400%) during lithiation/delithiation processes, which leads to electrode particle cracking, disintegration, and subsequent rapid capacity loss . Many efforts have been dedicated to accommodating the volume expansion of Si.…”