Conductive Polymer Binder for High-Tap-Density Nanosilicon Material for Lithium-Ion Battery Negative Electrode Application

TitleConductive Polymer Binder for High-Tap-Density Nanosilicon Material for Lithium-Ion Battery Negative Electrode Application
Publication TypeJournal Article
Year of Publication2015
AuthorsHui Zhao, Yang Wei, Ruimin Qiao, Chenhui Zhu, Ziyan Zheng, Min Ling, Zhe Jia, Ying Bai, Yanbao Fu, Jinglei Lei, Xiangyun Song, Vincent S Battaglia, Wanli Yang, Phillip B.Messersmith, Gao Liu
JournalNano Letters
Volume15
Issue12
Pagination7927 - 7932
Date Published09/2015
ISSN1530-6984
Abstract

High-tap-density silicon nanomaterials are highly desirable as anodes for lithium ion batteries, due to their small surface area and minimum first-cycle loss. However, this material poses formidable challenges to polymeric binder design. Binders adhere on to the small surface area to sustain the drastic volume changes during cycling; also the low porosities and small pore size resulting from this material are detrimental to lithium ion transport. This study introduces a new binder, poly(1-pyrenemethyl methacrylate-co-methacrylic acid) (PPyMAA), for a high-tap-density nanosilicon electrode cycled in a stable manner with a first cycle efficiency of 82%—a value that is further improved to 87% when combined with graphite material. Incorporating the MAA acid functionalities does not change the lowest unoccupied molecular orbital (LUMO) features or lower the adhesion performance of the PPy homopolymer. Our single-molecule force microscopy measurement of PPyMAA reveals similar adhesion strength between polymer binder and anode surface when compared with conventional polymer such as homopolyacrylic acid (PAA), while being electronically conductive. The combined conductivity and adhesion afforded by the MAA and pyrene copolymer results in good cycling performance for the high-tap-density Si electrode.

DOI10.1021/acs.nanolett.5b03003
Short TitleNano Lett.
Refereed DesignationRefereed