Nano‐Architectured Composite Anode Enabling Long‐Term Cycling Stability for High‐Capacity Lithium‐Ion Batteries

• DOI: 10.1002/smll.201906812
• Publication Date: 2020-02-24T12:35:17Z
• Authors: Praveen Kumar; Christopher L. Be...; Diana Zapata Domi...; Eric De Vito; Samuel Tardif; Stéphanie Pouget; Sandrine Lyonnard; Pierre‐Henri Jouneau
• Keywords: [PHYS]Physics [physics]; Li-ion batteries; 600; 02 engineering and technology; 540; 7. Clean energy; hierarchical structures; active alloys; [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]; lithium trapping; composite anodes; 0210 nano-technology

Failure mechanisms associated with silicon-based anodes are limiting the implementation of high-capacity lithium-ion batteries. Understanding aging mechanism that deteriorates anode performance and introducing novel-architectured composites offer new possibilities for improving functionality electrodes. Here, characterization nano-architectured composite composed active amorphous silicon domains (a-Si, 20 nm) crystalline iron disilicide (c-FeSi2 , 5-15 alloyed particles dispersed in a graphite matrix is reported. This unique hierarchical architecture yields long-term mechanical, structural, cycling stability. Using advanced electron microscopy techniques, nanoscale morphology chemical evolution upon lithiation/delithiation investigated. Due to volumetric variations Si during lithiation/delithiation, a-Si/c-FeSi2 alloy evolves from core-shell tree-branch type structure, wherein continuous network a-Si remains intact yielding capacity retention 70% after 700 cycles. The root cause electrode polarization, initial fading, swelling discussed has profound implications development stable