title: Conductive Polymer Binder for High-Tap-Density Nanosilicon Material for Lithium-Ion Battery Negative Electrode Application.
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.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Departments of Bioengineering and Materials Science and Engineering, UC Berkeley , Berkeley, California 94720, United States.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wei
authors.forename: Ruimin
authors.initials: R
authors.lastname: Qiao
authors.forename: Chenhui
authors.initials: C
authors.lastname: Zhu
authors.forename: Ziyan
authors.initials: Z
authors.lastname: Zheng
authors.forename: Min
authors.initials: M
authors.lastname: Ling
authors.forename: Zhe
authors.initials: Z
authors.lastname: Jia
authors.affiliation: Beijing Key Laboratory of Environmental Science and Engineering, School of Material Science and Engineering, Beijing Institute of Technology , Beijing 100081, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Bai
authors.forename: Yanbao
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Chongqing University , Chongqing, 400044, China.
authors.forename: Jinglei
authors.initials: J
authors.lastname: Lei
authors.forename: Xiangyun
authors.initials: X
authors.lastname: Song
authors.forename: Vincent S
authors.initials: VS
authors.lastname: Battaglia
authors.forename: Wanli
authors.initials: W
authors.lastname: Yang
authors.affiliation: Departments of Bioengineering and Materials Science and Engineering, UC Berkeley , Berkeley, California 94720, United States.
authors.forename: Phillip B
authors.initials: PB
authors.lastname: Messersmith
authors.forename: Gao
authors.initials: G
authors.lastname: Liu
mesh_terms: D011211:Electric Power Supplies; D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D049329:Nanostructures; D011108:Polymers / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*
chemical_list: D011108:Polymers; D008094:Lithium; D012825:Silicon
keywords: Conductive polymer binder; high tap density; lithium-ion battery; silicon nanoparticle; single molecule force