| 학회 | 한국재료학회 |
| 학술대회 | 2016년 가을 (11/16 ~ 11/18, 경주 현대호텔) |
| 권호 | 22권 2호 |
| 발표분야 | C. 에너지 재료 분과 |
| 제목 | Si-based anode materials for next-generation lithium ion Batteries |
| 초록 | Recently, Si–based materials, an alloy/de–alloy type, are regarded as one of the most attractive candidates to replace carbonaceous anode materials in LIBs owing to their high theoretical specific capacity and low initial irreversible capacity compared to conversion–type electrode materials. Furthermore, Si is a readily available, abundant and eco-friendly material that can be refined into an extremely pure form with a large mass. The main obstacle of Li–Si alloys is the massive volume change that results in electrode pulverization, the loss of the electrical contacts, and drastic capacity fading during the alloying/de–alloying reactions. To address these problems, I’d like to introduce two approaches. First, we provide a facile and cost-effective metal-assisted chemical etching (MACE) method to synthesize conformally Ag-coated SiNWs with controlled redox processes, which provides structural and electrical effects on Si negative electrodes at the same time. The combinations of the SiNW geometry and AgNP coatings are beneficial in preventing pulverization or crumbling of Si during cycling, therefore, excellent electrochemical performances are achieved. Secondly, Silicon monoxide (SiO) has been received much attention as an alternative choice instead of pure Si anode materials. When SiO anode undergoes lithiation processes, Li oxide (Li2O) and Li silicates (Li4SiO4) are mainly formed and that act as a more stable phase than the Li-Si alloys during long cycles. Moreover, SiO is thermodynamically unstable at all temperatures, it can be easily transformed into nano-crystalline Si (nc-Si) and SiOx during heat treatment, triggering a disproportionation reaction. Therefore, we fabricated nc-Si embedded SiOx negative electrode materials using thermal disproportionation in order to enhance the reversible capacity for high performance LIBs. Furthermore, we have found that the electrochemical performance at high current rate, and the electrical conductivity are greatly improved by B-doping on SiO negative electrode materials using the facile spin-on dopants (SOD) technique. Our approaches provide a simple and effective route to prepare high-performance negative electrode materials in future LIB applications for electrical transportation. References [1] Baek et al. “Facile synthesis of Ag-coated silicon nanowires as anode materials for high-performance rechargeable lithium battery” J. Alloys Compd. 660 (2016) 387-391 [2] Woo et al. “Improved electrochemical performance of boron-doped SiO negative electrode materials in lithium-ion batteries” J. Power Sources 299 (2015) 2531 |
| 저자 | 백성호 |
| 소속 | 대구경북과학기술원 나노에너지융합연구부 |
| 키워드 | <P>실리콘; 음극; 리튬이차전지; 나노와이어</P> |
