Abstract
Silicon is considered a promising candidate for lithium-ion battery anodes because of its exceptionally high capacity. However, employing Si in real applications remains a challenge, owing to dramatic reduction in the capacity after a few cycles. Redesigning the advanced electrode structure, including the available free volume and continuous conductive scaffold, may potentially circumvent this problem. Here, we demonstrate a new method of creating binder- and conductive additive-free three-dimensional (3D) porous network Si@C electrodes via fibrin hydrogel templating followed by pyrolysis. Hydrogen bonds between hydroxyl groups on Si and amides of fibrin enable the hierarchical 3D structures. These comprise well-distributed Si nanoparticles (SiNPs) in carbon frameworks, with each particle conformally encapsulated by the carbon layer. We confirm that carbon is doped with nitrogen and that pyridinic N and pyrrolic N are the predominant configurations. The 3D Si@C electrode exhibits a good rate performance (capacity of 730 mAh g−1 at 1000 mA g−1 (0.5C, Si + C basis)) and also a stable cycling property (54% capacity retention after 500 cycles at 500 mA g−1). Compared to a conventional mixture (SiNPs/alginate/Super P), the 3D Si@C electrode exhibits significantly improved electrochemical properties.
Original language | English |
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Article number | 149439 |
Journal | Applied Surface Science |
Volume | 551 |
DOIs | |
Publication status | Published - 2021 Jun 15 |
Keywords
- 3D Si@C network
- Fibrin template
- Hydrogen bonding
- Lithium-ion batteries
- N-doped C
- Pyrolysis
ASJC Scopus subject areas
- Chemistry(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films