Switched-capacitor-convertors based on fractal design for output power management of triboelectric nanogenerator

Abstract

Owing to the advantages of integration and being magnet-free and light-weight, the switched-capacitor-convertor plays an increasing role compared to traditional transformer in some specific power supply systems. However, the high output impedance and switching loss largely reduces its power efficiency, due to imperfect topology and transistors. Herein, we propose a fractal-design based switched-capacitor-convertors with characteristics including high conversion efficiency, minimum output impedance, and electrostatic voltage applicability. As a double-function output power management system for triboelectric nanogenerators, it delivers over 67 times charge boosting and 954 W m−2 power density in pulse mode, and achieves over 94% total energy transfer efficiency in constant mode. The establishment of the fractal-design switched-capacitor-convertors provides significant guidance for the development of power management toward multi-functional output for numerous applications. The successful demonstration in triboelectric nanogenerators also declares its great potential in electric vehicles, DC micro-grids etc.

Boosting output performance of sliding mode triboelectric nanogenerator by charge space-accumulation effect

“…To boost the output performance, numerous research works have been carried out for enhancing the surface charge density of CS-TENG, such as the inner material optimization 29 , surface physical/chemical modification 30 , ion injection 31 , environmental control 32 , etc. 33 – 36 . A record high charge density of 2.38 mC m −2 was achieved by charge excitation and quantifying contact in the latest work 37 .…”

Progress inTENGtechnology—A journey from energy harvesting to nanoenergy and nanosystem

“…The first phase of the roadmap of TENG technology is about the in-depth understanding of the mechanisms for energy-boosting and achievable form of a voltage (alternative current, AC, and direct current, DC). [81][82][83][84][85][86][87][88][89][90][91][92][93][94] Beyond taking advantage of the micro/nano surface structures, the pre-charging process, the external circuit units (diode, switch, or charge pump), and the design of the mechanical structure (surface pattern and operation programming) would be the novel research direction for efficiency improvement. For example, a coupling of the triboelectrification and dielectric polarization from the ferroelectric material was reported in 2017 with an energy density of 430 μC/m 2 .…”

“…With the development of new mechanisms for energyboosting and achievable form of a voltage (AC and DC) in TENG technology, the approaches for the stable and expectation charges could be discussed, such as the composite materials, the external circuit units (diode, switch, or charge pump), and the design of the mechanical structure (surface pattern and operation programming). [82][83][84][85][86][87][88][89][90][91][92][93][94]109,110 The TENG technology as power sources would dramatically drive the development trends of the era of the coming 5G and IoT. To help the readers to understand the development of the self-powered sensors in TENG technology, the multi-functional sensors (physical sensors, chemical/gas sensors, advanced designed multi-sensors) are discussed along with the energy harvesting as follows.…”

Network Topology Optimization of Triboelectric Nanogenerators for Effectively Harvesting Ocean Wave Energy

“…With the gifted advantages such as simple structure, abundant material options, and low fabrication cost ( Wang, 2014 ; Wang et al., 2015 ; Zhang et al., 2014 ; Zhao et al., 2019 ), the TENGs have made remarkable achievements in the application field of micropower/nanopower sources ( Ahmed et al., 2020 ; Chandrasekhar et al., 2017 ; Deng et al., 2020 ; Jin et al., 2020 ; Liu et al., 2020a ; Lu et al., 2019 ; Quan et al., 2015 ; Šutka et al., 2020 ; Yan et al., 2020 ; Yang et al., 2013 , 2014 ; Zou et al., 2020 ), self-powered sensors ( Bu et al, 2018a , 2018b ; Fu et al., 2017 ; Guo et al., 2018 ; Meng et al., 2020 ; Pang et al., 2015 ; Su et al., 2020a , 2020b ; Wang et al., 2018a ; Zhou et al., 2020b , 2020c ), high-voltage power sources ( Bu et al., 2019 ; Fan et al., 2015 ; Nie et al., 2018 ; Yang et al., 2019a ), and large-scale blue energy ( Chen et al., 2020b ; Liang et al., 2019 ; Rodrigues et al., 2020 ; Xu et al, 2017 , 2018 ; Yang et al., 2019b ; Zhang et al., 2016a ), which is to harvest the low frequency, irregular, and multidirectional water wave energy. Recently, some remarkable works have been developed to improve the performance of TENGs ( Liu et al., 2020b , 2020c ; Wang et al., 2018b ). To further improve the efficiency of the TENG for harvesting water wave energy, some literatures focus on the new structures of TENGs.…”