상세정보
학술지
Performance Improvements of Pouch-Type Flexible Thin-Film Lithium-Ion Batteries by Modifying Sequential Screen-Printing Process
- 발행일
- 201408
- 출처
- Electrochimica Acta, v.138, pp.294-301
- ISSN
- 0013-4686
- 출판사
- Elsevier
- 협약과제
- 13VB4800, 중대형 전고체 리튬이차전지용 유무기 하이브리드 고체전해질, 이영기
- 초록
- A pouch-type flexible thin-film lithium-ion battery is fabricated by sequential screen-printing (wet) processes to produce consecutive layers of a current collector, positive and negative electrodes, and a gel polymer electrolyte. Optimum conditions of each process are determined by adjusting the paste or slurry compositions to achieve lower surface resistance of each layer (current collector and electrodes) and higher ionic conductivity of the gel polymer electrolyte. The fabricated flexible thin-film lithium-ion battery (5.5 × 5.5 cm2, 325 μm thick) shows superior electrochemical performance, including an energy density of 292.3 Wh L-1 based on electrode size (4.0 × 4.0 cm2), an initial discharge capacity of 2.5 mAh cm-2 per electrode area, and capacity retention ratio of over 68% at the 50th cycle. To further improve the battery performance, the wet processes are modified by adopting hybrid (dry-wet) processes, which mainly consist of the formation of metallic current collector layers (Al and Cu) using a thermal evaporator and another optimized gel polymer electrolyte, to achieve an energy density of 332.8 Wh L-1 and capacity retention ratio of 84% at the 50th cycle. Cell flexibility is also confirmed by stable open circuit voltages after the system is subjected to several hundred iterations of bending, stretching, and even folding. There is the possibility that the suggested wet and dry-wet processes can be expanded to a high-speed mass-production roll-to-roll process. © 2014 Elsevier Ltd.
- KSP 제안 키워드
- Dry-wet, Electrode area, Energy density, Gel polymer electrolyte, High Speed, Ion batteries, Negative electrodes, Open circuit voltage(VOC), Optimum condition, Positive and negative, Printing process