title: The effect of nanoparticle packing on capacitive electrode performance.
abstract: Nanoparticles pack together to form macro-scale electrodes in various types of devices, and thus, optimization of the nanoparticle packing is a prerequisite for the realization of a desirable device performance. In this work, we provide in-depth insight into the effect of nanoparticle packing on the performance of nanoparticle-based electrodes by combining experimental and computational findings. As a model system, polypyrrole nanospheres of three different diameters were used to construct pseudocapacitive electrodes, and the performance of the electrodes was examined at various nanosphere diameter ratios and mixed weight fractions. Two numerical algorithms are proposed to simulate the random packing of the nanospheres on the electrode. The binary nanospheres exhibited diverse, complicated packing behaviors compared with the monophasic packing of each nanosphere species. The packing of the two nanosphere species with lower diameter ratios at an optimized composition could lead to more dense packing of the nanospheres, which in turn could contribute to better device performance. The dense packing of the nanospheres would provide more efficient transport pathways for ions because of the reduced inter-nanosphere pore size and enlarged surface area for charge storage. Ultimately, it is anticipated that our approach can be widely used to define the concept of "the best nanoparticle packing" for desirable device performance.
authors.affiliation: Department of Polymer Engineering, Graduate School, Chonnam National University, Gwangju 61186, South Korea.
authors.forename: Younghee
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Polymer Engineering, Graduate School, Chonnam National University, Gwangju 61186, South Korea.
authors.forename: Seonmyeong
authors.initials: S
authors.lastname: Noh
authors.affiliation: Department of Polymer Engineering, Graduate School, Chonnam National University, Gwangju 61186, South Korea.
authors.forename: Min-Sik
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Department of Polymer Engineering, Graduate School, Chonnam National University, Gwangju 61186, South Korea.
authors.forename: Hye Jeong
authors.initials: HJ
authors.lastname: Kong
authors.affiliation: Department of Polymer Engineering, Graduate School, Chonnam National University, Gwangju 61186, South Korea.
authors.forename: Kyungun
authors.initials: K
authors.lastname: Im
authors.affiliation: BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejon 34141, South Korea.
authors.forename: Oh Seok
authors.initials: OS
authors.lastname: Kwon
authors.affiliation: Department of Textiles, Merchandising, and Fashion Design, Seoul National University, Seoul 08826, South Korea. sungmin0922@snu.ac.kr.
authors.forename: Sungmin
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Polymer Engineering, Graduate School, Chonnam National University, Gwangju 61186, South Korea and School of Polymer Science and Engineering, Chonnam National University, Gwangju 61186, South Korea. hyoon@chonnam.ac.kr.
authors.forename: Hyeonseok
authors.initials: H
authors.lastname: Yoon