Interfacial study of the role of SiO2 on Si anodes using electrochemical quartz crystal microbalance

Abstract

One of the challenges associated with silicon as an anode material for Li-ion batteries is the formation of an unstable solid-electrolyte interphase which, forms continuously while consuming lithium and other components; and consequently contributes to irreversible capacity. To elucidate some of the details of the formation and subsequent dissolution of species formed during lithiation of silicon anodes we have produced thin film silicon electrodes and analyzed them during lithiation and delithiation using an electrochemical quartz microbalance with in-situ dissipation (EQCM-D). Measurements were conducted on electrodes with silicon alone and silicon with a silicon dioxide coating, and in EC:EMC and EC:DEC:FEC based electrolytes. Mass loss during lithiation was observed in both solvents systems when an oxide layer was present on the surface of the electrode. Solid state and solution NMR measurements indicate that the formation and dissolution of Li 2 O is the most likely cause of mass loss. AbstractOne of the challenges associated with silicon as an anode material for Li-ion batteries is the

Electrodeposited copper foams as substrates for thin film silicon electrodes

“…For many interfacial electrochemical materials studies, thin films electrodes are ideal because of their well-defined surface area, the absence of binder or conductive additive, and experimental control over crystallinity [3,7,8,13]. These advantages can help researchers better understand various electrode processes, surface reactions, and the effect of cycling on specific physical characteristics of the active material.…”

“…These electrodes advantages include having no organic binder to complicate spectroscopic analysis of the SEI layer and they are amenable to electrolyte stability studies using a variety of spectroscopic techniques, e.g. EQCM [6,7]. At a materials level, silicon electrodes are limited by the slow diffusion of lithium through silicon and the resulting active material inhomogeneity at various states of charge as limiting electrochemical performance [8].…”

Synthesis of Robust Silicon Nanoparticles@Void@Graphitic Carbon Spheres for High‐Performance Lithium‐Ion‐Battery Anodes

“…[28] In order to further check the chemical states of elements in Si@void@C spheres, XPS was conducted and shown in Figure 5c, which displays binding energy at 285 eV (C 1 s), 532 eV (O 1s) and 100.4 eV (Si 2p) respectively. [31,32] The chemical state of silicon was further presented in Figure 5d, binding energy at 100.4 eV indicates Si 2p, while weak peak at 102.6 eV shows the SiÀO state, this can be ascribed to ultratrace of SiO, which mainly comes from contaminate and residual hydroxyl in carbon matrix.…”

“…The chemical state of silicon was further presented in Figure 5d, binding energy at 100.4 eV indicates Si 2p, while weak peak at 102.6 eV shows the SiÀO state, this can be ascribed to ultratrace of SiO, which mainly comes from contaminate and residual hydroxyl in carbon matrix. [31,32]…”

Effect of Fluoroethylene Carbonate in the Electrolyte for LiNi0.5Mn1.5O4 Cathode in Lithium-ion Batteries

“…Simultaneously, the electrolyte plays an important role in the formation of a stable passivation film on the electrode surface, whose area increases continually because of pulverization. Among several candidates, electrolytes with large amounts of fluoroethylene carbonate (FEC) additive have been studied to cover the newly exposed electrochemically active surfaces [9][10][11]. The electrolytes for conventional graphite anodes in LIBs usually contain a small quantity of additives, less than 10 vol%.…”