Improving Cycling Performance of Si-Based Lithium Ion Batteries Anode with Se-Loaded Carbon Coating

Abstract

Poor cycling stability and rate capability significantly limit the commercial applications of silicon (Si) anode, due to the huge volume change and poor electronic and ionic conductivity of Si. Combining Si with SiO2 and carbon (C) can effectively improve the structural stability of electrode, but common carbon coating still suffers from the problem of comparatively low ionic conductivity. Here we designed and developed a core–shell structural Si@SiO2@C/Se anode with high ionic conductivity and structural stability by loading selenium (Se) into a carbon framework. Remarkably, it exhibits a high rate capability (612 mAh g–1 at 8 A g–1) and ultrahigh initial columbic efficiency (80.8%), which is much higher than ordinary Si/SiO2-based anode (50–60%). In addition, it shows an excellent cycling performance, which is about 1560 mAh g–1 after 150 charging/discharging cycles at the current density of 0.5 A g–1. This work provides a new technology to design high capacity alloy-type lithium-ion batteries (LIBs) anode.

Lithium Substituted Poly(acrylic acid) as a Mechanically Robust Binder for Low-Cost Silicon Microparticle Electrodes

“…Silicon (Si) has been considered a high capacity negative electrode material for the next generation lithium ion batteries (LIBs) to increase the range of electric vehicles. However, the insufficient cycle life, caused by the volume change-induced fracture of Si and an unstable solid electrolyte interphase (SEI), impedes the commercialization of Si-based electrodes. − To mitigate the degradation of Si electrodes, intensive efforts have been devoted to developing nanostructured Si, including Si nanoparticles (SiNPs), , Si nanowires, , and core–shell structured SiNPs, , as they have large surface tension and are less prone to fracture. , Nanostructured Si materials have been widely used for preparing composite electrodes of Si/C, − Si/metal oxides, − and Si/metal alloys , to alleviate volume expansion and electronic isolation during cycling. However, current approaches for preparing Si nanomaterials are complex and expensive to scale up.…”

Improved Performance of Li-Added Mo–Nb Oxide as the Anode for Li-Ion Batteries with N-Carbon Coating

“…The proportion of capacitance control steadily increases as the scan rate increases, indicating a rapid charge and discharge process at a higher scan rate. The lithium ion diffusion coefficient on MNO-based anodes at room temperature was estimated using the Randles–Sevcik equation . The values were 2.2 × 10 –13 , 1.97 × 10 –13 , and 8.46 × 10 –13 cm 2 S –1 for MNO, Li-MNO, and Li-MNO/NC, respectively.…”

“…The lithium ion diffusion coefficient on MNO-based anodes at room temperature was estimated using the Randles−Sevcik equation. 45 The values were 2.2 × 10 −13 , 1.97 × 10 −13 , and 8.46 × 10 −13 cm 2 S −1 for MNO, Li-MNO, and Li-MNO/NC, respectively. It is obvious that MNO and Li-MNO had a similar diffusion coefficient, but Li-MNO/NC had a much higher diffusion coefficient as compared to MNO or Li-MNO.…”

In Situ Polymerized and Imidized Si@Polyimide Microcapsules with Flexible Solid‐Electrolyte Interphase and Enhanced Electrochemical Activity for Li‐Storage

“…Consequently, serious pulverization and cracking of silicon anode occurs during electrochemical cycles, resulting in gradual loss of electric contact and deterioration of cycling performance. [17][18][19][20][21] In addition, the repetitive volume expansion/ contraction of silicon anode during Li-ion insertion/extraction make it difficult to form a stable solid electrolyte interphase (SEI), leading to continuous decomposition of electrolytes and severe irreversible lithium consumption.…”