Colloidal Probe 원자현미경을 이용한 2차전지 전극용 폴리머 바인더의 응착 및 마찰 특성 평가
Assessment of Adhesion and Frictional Properties of Polymer Binders for Secondary Cells using Colloidal Probe Atomic Force Microscope
0
조회
0
다운로드
2
인용
0
참고문헌
키워드
초록
In lithium-ion batteries (LIBs), the stress induced by the volume change of an electrode during charge–discharge processes may often cause the mechanical integrity of the electrode to degrade. Polymer binders with enhanced mechanical properties are preferred for improved mechanical integrity and cycling stability of the electrode. In addition, given that sliding and shearing between the polymer binder and components in the electrode may readily occur, frictional and adhesion characteristics of the polymer binder may play a critical role in the mechanical integrity of the electrode. In this study, frictional and adhesion characteristics of polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) were investigated using a colloidal probe atomic force microscope. Friction loops were obtained under various normal forces ranging from 0 to 159 nN in air and electrolyte and then the interfacial shear strengths of PAN and PVDF in air were calculated to be 1.4 ± 0.5 and 1.3 ± 0.3 MPa, respectively. The results show that in electrolyte, interfacial shear strength of PAN decreased slightly (1.2 ± 0.2 MPa), whereas that of PVDF decreased drastically (0.06 ± 0.01 MPa). Decreases in mechanical properties and adhesion in electrolyte may be responsible for the decrease in interfacial shear strength in electrolyte. The findings from this study may be helpful in developing polymer binders to improve the mechanical integrity of electrodes in LIBs.
Abstract
In lithium-ion batteries (LIBs), the stress induced by the volume change of an electrode during charge–discharge processes may often cause the mechanical integrity of the electrode to degrade. Polymer binders with enhanced mechanical properties are preferred for improved mechanical integrity and cycling stability of the electrode. In addition, given that sliding and shearing between the polymer binder and components in the electrode may readily occur, frictional and adhesion characteristics of the polymer binder may play a critical role in the mechanical integrity of the electrode. In this study, frictional and adhesion characteristics of polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) were investigated using a colloidal probe atomic force microscope. Friction loops were obtained under various normal forces ranging from 0 to 159 nN in air and electrolyte and then the interfacial shear strengths of PAN and PVDF in air were calculated to be 1.4 ± 0.5 and 1.3 ± 0.3 MPa, respectively. The results show that in electrolyte, interfacial shear strength of PAN decreased slightly (1.2 ± 0.2 MPa), whereas that of PVDF decreased drastically (0.06 ± 0.01 MPa). Decreases in mechanical properties and adhesion in electrolyte may be responsible for the decrease in interfacial shear strength in electrolyte. The findings from this study may be helpful in developing polymer binders to improve the mechanical integrity of electrodes in LIBs.
참고문헌 (17)
- Wu, H., "Designing Nanostructured Si anodes for High Energy Lithium Ion Batteries", Nano Today, 7, pp.414~429 (2012)
- Beaulieu, L. Y., "Reaction of Li with Alloy Thin Films Studied by in situ AFM", J. Elec-trochem. Soc., 150, pp.A1457~A1464 (2003)
- Magasinski, A., "Toward Efficient Binders for Li-ion Battery Si-based Anodes: Polyacrylic acid", ACS Appl. Mater. Interfaces, 2, pp.3004~3010 (2010)
- Yang, H. S., "Performance Enhancement of Silicon Alloy-based Anodes using Thermally Treated Poly (amide imide) as a Polymer Binder for High Perfor-mance Lithium-ion Batteries", Langmuir, 32, pp.3300~3307 (2016)
- Ling, M., "Multifunctional SA-PProDOT Binder for Lithium Ion Batteries", Nano Lett., 15, pp.4440~4447 (2015)
- Sethuraman, V. A., "Stress Evo-lution in Composite Silicon Electrodes during Lithi-ation", Delithiation, 2013, pp.160, A739~A746
- Nguyen, Q. D., "Nanome-chanical Properties of Polymer Binders for Li-ion Batteries Probed with Colloidal Probe Atomic Force Microscopy", Polym. Test., 76, pp.245~253 (2019)
- Ducker, W. A., "Direct Measurement of Colloidal Forces using an Atomic Force Microscope", Nature, 353, pp.239~241 (1991)
- Hutter, J. L., "Calibration of Atomic-force Microscope Tips", Rev. Sci. Instrum., 64, pp.1868~1873 (1993)
- 정구현, "AFM을 이용한 나노스케일 힘의 정량적 측정", 한국트라이볼로지학회지, 28(2), pp.62~69 (2012), 한국트라이볼로지학회[DOI]
- Perni, S., "Toluidine Blue-containing Polymers Exhibit Potent Bactericidal Activity When Irradiated with Red Laser Light", J. Mater. Chem., 19, pp.2715~2723 (2009)
- Mallapragada, S. K., "Dissolution Mechanism of Semicrystalline Poly (vinyl alcohol)in Water", J. Polym. Sci. B Polym. Phys., 34, pp.1339~1346 (1996)
- Johnson, K. L., "Surface Energy and the Contact of Elastic Solids", Proc. R. Soc. A, 324, pp.301~313 (1971)
- Weisenhorn, A. L., "Measuring Adhesion, Attraction, and Repul-sion between Surfaces in Liquids with an Atomic-force Microscope", Phys. Rev. B, 45, pp.11226~11232 (1992)
- Hertz, H. R., "Uber die beruhrung fester elastischer korper und uber die harte", J. Reine Angew. Math., 92, pp.156~171 (1882)
- Briscoe, B., "Rheology of Solvent-cast Polymer Films", J. Appl. Polym. Sci, 28, pp.3827~3848 (1983)
- Gracias D. H., "Continuum Force Microscopy Study of the Elastic Modulus, Hardness and Friction of Polyethylene and Polypropylene Sur-faces", Macromolecules, 31, pp.1269~1276 (1998)