On the Specific Capacity and Cycle Stability of Si@void@C Anodes: Effects of Particle Size and Charge/Discharge Protocol

On the Specific Capacity and Cycle Stability of Si@void@C Anodes: Effects of Particle Size and Charge/Discharge Protocol

Silicon has the potential to be a high-performance anode material, but its practical application is impeded by huge volume expansion during lithiation. Many studies have revealed that the huge volume expansion problem can be mitigated by introducing engineered voids into Si/C core–shell structures....

Full description

Saved in:
Bibliographic Details
Published in:Batteries (Basel) Vol. 8; no. 10; p. 154
Main Authors: Liu, Bingyu, Luo, Mei, Wang, Ziyong, Passolano, Christopher, Shaw, Leon
Format: Journal Article
Language:English
Published: Basel MDPI AG 01-10-2022
Subjects:
Anodes
Carbon
charge/discharge protocol
Composition
Core-shell structure
cycle stability
Discharge
Electrode materials
Electrodes
Electrolytes
Energy
Etching
Graphite
Li-ion batteries
Molecular weight
Nanoparticles
Particle size
Scanning electron microscopy
Si/C core–shell structure
Silicon
silicon anodes
Solid electrolytes
specific capacity
Stability
Transmission electron microscopy
United States
St Louis Missouri
United States > US
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Silicon has the potential to be a high-performance anode material, but its practical application is impeded by huge volume expansion during lithiation. Many studies have revealed that the huge volume expansion problem can be mitigated by introducing engineered voids into Si/C core–shell structures. In this study, a Si/C core/shell structure with engineered voids, termed Si@void@C, is investigated for its specific capacity and cycle stability as a function of particle size and charge/discharge protocol. The study shows that finer Si@void@C particles result in higher specific capacities, but with little impact on the cycle stability. Further, lower and upper cutoff voltages in charge/discharge have a profound impact on the specific capacity and cycle stability. Importantly, cutoff voltages in formation cycles have long-lasting effects on the cycle stability, indicating the critical role of forming a robust solid electrolyte interphase (SEI) layer during formation cycles. Using a constant current charge followed by potentiostatic hold charge can further improve the cycle stability and minimize the sharp capacity decay in the first 20–40 cycles. With proper choices of charge/discharge protocols, the specific capacities of Si@void@C anodes at the electrode level are 66.8%, 38.2% and 22.7% higher than those of graphite anodes at the 1st, 300th and 500th cycles, respectively, proving that Si@void@C has promising potential to replace graphite anodes for practical applications in the future.
ISSN:2313-0105
2313-0105
DOI:10.3390/batteries8100154