A new polymeric binder for silicon-carbon nanotube composites in lithium ion battery
A new polymeric binder for silicon-carbon nanotube composites in lithium ion battery / Joonwon Bae, Sang-Ho Cha, Jongnam Park
p. 826-831 ; 29 cm
수록자료: Macromolecular research. Polymer Society of Korea. Vol.21 no.7(2013 July), p. 826-831 21:7<826 ISSN 1598-5032 저자: Joonwon Bae, Department of Applied Chemistry, Dongduk Women’s University E-MAIL: firstname.lastname@example.org 저자: Sang-Ho Cha, Department of Chemical Engineering, Kyonggi University 저자: Jongnam Park, Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology(UNIST) E-MAIL: email@example.com
We introduced polyethyleneimine (PEI) as a new binder for silicon (Si)-carbon nanotube (CNT) anode materials in lithium ion batteries (LIBs). The PEI binder was chosen to enhance the binding of electrode material containing Si-CNT nanocomposites through the formation of a PEI thin layer on the surfaces of CNTs. It was expected that the spontaneous electrostatic interactions between weakly charged PEI molecules with CNT surfaces could promote the binding performance. In other words, the formation of solid-electrolyte interface (SEI) could be suppressed owing to the effect of dominant electrostatic interactions between PEIs and CNTs. Zeta potential analyses demonstrated the real presence of electrostatic interactions between PEIs and CNTs. Accordingly, lithium battery half-cell tests showed that improved capacity retention behavior was observed in the sample with PEI than that with polyvinyldifluoride (PVDF) binder. Remarkably, for the case of Si-CNT anode materials prepared without or with relatively less amount of CNT, a higher reduction in capacity was observed with PEI binder than with PVDF. An additional advantage of the incorporation of PEI binder is an increase of initial coulombic efficiency approximately 5%∼10%. Consequently, all these findings support that PEI is highly desirable as an alternative binder for electrode materials containing CNT.