Synergistic Lithium Storage in Silica–Tin Composites Enables a Cycle-Stable and High-Capacity Anode for Lithium-Ion Batteries

Abstract

Silica (SiO2) is considered as a promising candidate anode material for next-generation lithium-ion batteries (LIBs) owing to its low cost, abundant reserve on Earth, and relatively high theoretical specific capacity. However, the development of SiO2-based anode materials has been impeded by their poor electrical conductivity and sluggish charge-transfer kinetics. Herein, porous SiO2/tin (SiO2@Sn) composites with tunable SiO2 to Sn molar ratios are fabricated using a scalable, simple, and low-cost ball-milling and low-temperature thermal-melting combined method. It is found that the Sn phase can significantly improve the diffusion and migration kinetics of Li in the composites, whereas the SiO2 to Sn molar ratio plays a key role in the mechanical integrity and subsequent cycling behaviors of the composite electrodes. By optimizing the molar ratio of SiO2/Sn to 10:1, the synergistic effect of Li storage between SiO2 and Sn can lead to the simultaneous achievement of improved Li kinetics and ensured mechanical integrity, contributing to the excellent electrochemical performance of the composite with a large reversible capacity of 613 mAh g–1 at 100 mA g–1, a remarkable rate capability of 450 mAh g–1 retained at 1000 mA g–1, and long-term cycling durability with ∼95% capacity retention over 200 cycles.

Fabrication of Sustainable Hybrid MOF/Silica Electrodes for Current Lithium-ion Batteries and Beyond

“…Despite these desirable features, silica shows a problematic volume change during the cycling process, even though it less than that of elemental silicon . Besides, silica possesses poor electronic conductivity and a relatively low initial Coulombic efficiency (CE) caused by the irreversible formation of lithium silicates and Li 2 O during the initial discharge process on the electrode surface . One effective method for accommodating the SiO 2 volume change and improving its electrical conductivity is to integrate silica with a carbonaceous matrix .…”

“…10 Besides, silica possesses poor electronic conductivity and a relatively low initial Coulombic efficiency (CE) caused by the irreversible formation of lithium silicates and Li 2 O during the initial discharge process on the electrode surface. 11 One effective method for accommodating the SiO 2 volume change and improving its electrical conductivity is to integrate silica with a carbonaceous matrix. 12 Moreover, it was also observed that the presence of heteroatoms such as nitrogen within carbon/SiO 2 composites can increase the reactivity of the active material, thereby enhancing the capacity.…”

Si/SiO2@Graphene Superstructures for High‐Performance Lithium‐Ion Batteries

“…[ 57 ] The Si/SiO 2 @G‐S anode exhibits a significantly smallest R ct among the three electrodes before cycling, suggesting fast charge‐transfer rate between the electrode and electrolyte for Si/SiO 2 @G‐S (Figure 6j). [ 58 ] To further clarify the stable SEI phase, different cycles of EIS of the Si/SiO 2 @G‐S electrode at full delithiation state are obtained in Figure 6k. After 50th and 100th cycle of Si/SiO 2 @G‐S, there is a little change in R ct values.…”

Facile Synthesis of Carbon Nanospheres with High Capability to Inhale Selenium Powder for Electrochemical Energy Storage

“…DLi + ∝ 1/σ 2 , (2) This equation is utilized to determine the diffusion coefficient for the composite before and after cycling [37][38][39][40], and the obtained values for the σ for fresh and for the cell after 70 cycles are 472.2 and 1303.89, respectively, as illustrated in Figure 5b.…”