Research Article Dielectric Manipulated Charge Dynamics in Contact Electrification Kunming Shi, 1 Bin Chai, 1 Haiyang Zou, 2 Daomin Min, 3 Shengtao Li, 3 Pingkai Jiang, 1 and Xingyi Huang 1 1 Department of Polymer Science and Engineering, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China 2 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245, USA 3 State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China Correspondence should be addressed to Xingyi Huang; xyhuang@sjtu.edu.cn Received 5 November 2021; Accepted 6 January 2022; Published 1 February 2022 Copyright © 2022 Kunming Shi et al. Exclusive Licensee Science and Technology Review Publishing House. Distributed under a Creative Commons Attribution License (CC BY 4.0). Surface charge density has been demonstrated to be significantly impacted by the dielectric properties of tribomaterials. However, the ambiguous physical mechanism of dielectric manipulated charge behavior still restricts the construction of high-performance tribomaterials. Here, using the atomic force microscopy and Kelvin probe force microscopy, an in situ method was conducted to investigate the contact electrification and charge dynamics on a typical tribomaterial (i.e., BaTiO 3 /PVDF-TrFE nanocomposite) at nanoscale. Combined with the characterization of triboelectric device at macroscale, it is found that the number of transferred electrons increases with contact force/area and tends to reach saturation under increased friction cycles. The incorporated high permittivity BaTiO 3 nanoparticles enhance the capacitance and electron trapping capability of the nanocomposites, efficiently inhibiting the lateral diffusion of electrons and improving the output performance of the triboelectric devices. Exponential decay of the surface potential is observed over monitoring time for all dielectric samples. At high BaTiO 3 loadings, more electrons can drift into the bulk and combine with the induced charges on the back electrode, forming a large leakage current and accordingly accelerating the electron dissipation. Hence, the charge trapping/storing and dissipating, as well as the charge attracting properties, should be comprehensively considered in the design of high-performance tribomaterials. 1. Introduction Contact electrification brings about charge transfer between two materials during contact or friction process [1–3], and this universally existing phenomenon is also considered to be derived from the difference of work functions or surface potentials between the contacting materials [4–6]. Though the triboelectric charges are commonly regarded to be detri- mental for electronic circuits and systems, they have been successfully utilized in today’s advanced technologies, including photocopying [7], laser printing [8], electrostatic separation [9], painting [10], field-effect transistor [11–13], and mechanical energy harvesting [14–16]. In the field of energy harvesting, triboelectric devices, a new sustainable power source based on contact electrifica- tion and electrostatic induction effect, can convert ambient mechanical energy to electrical energy [17–21]. The tribo- electric charges on material surface serve as an electrostatic induction source to generate electricity, and the output volt- age and current are both dictated by surface charge density [22, 23]. Hence, boosting the amount of triboelectric charge during contact electrification is essential for the improve- ment of triboelectric device performance. The dielectric properties of the tribomaterials play a key role in triboelec- tric performance [24–26]. Organic dielectrics-based devices exhibit a limited output performance owing to their rela- tively low permittivity. Incorporating high permittivity (high-k) fillers into the polymer matrix has been demon- strated to be efficient to improve the surface charge density and triboelectric performance [27–31]. Though this strategy has been well established in the construction of tribomater- ials, the physical interpretation of dielectric manipulated charge dynamics (charge transfer, charge distribution, and charge dissipation) still remain ambiguous, which restricts AAAS Research Volume 2022, Article ID 9862980, 12 pages https://doi.org/10.34133/2022/9862980