Article

Hybridizing Energy Conversion and Storage in a Mechanical-to-Electrochemical Process for Self-Charging Power Cell

School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States.
Nano Letters (Impact Factor: 13.59). 08/2012; 12(9):5048-54. DOI: 10.1021/nl302879t
Source: PubMed

ABSTRACT

Energy generation and energy storage are two distinct processes that are usually accomplished using two separated units designed on the basis of different physical principles, such as piezoelectric nanogenerator and Li-ion battery; the former converts mechanical energy into electricity, and the latter stores electric energy as chemical energy. Here, we introduce a fundamental mechanism that directly hybridizes the two processes into one, in which the mechanical energy is directly converted and simultaneously stored as chemical energy without going through the intermediate step of first converting into electricity. By replacing the polyethylene (PE) separator as for conventional Li battery with a piezoelectric poly(vinylidene fluoride) (PVDF) film, the piezoelectric potential from the PVDF film as created by mechanical straining acts as a charge pump to drive Li ions to migrate from the cathode to the anode accompanying charging reactions at electrodes. This new approach can be applied to fabricating a self-charging power cell (SCPC) for sustainable driving micro/nanosystems and personal electronics.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Photoelectrochemical (PEC) processes are fundamental for photon water splitting and energy storages. The key to the PEC efficiency is dictated by the charge generation and separation processes. In this chapter, we present the piezoelectric on PEC, in which a consistent enhancement or reduction of photocurrent was observed when tensile or compressive strains were applied to the ZnO anode, respectively. The photocurrent variation is attributed to a change in barrier height at the ZnO/electrolyte interface. We also introduce a fundamental mechanism that directly hybridizes the two processes into one, using which the mechanical energy is directly converted and simultaneously stored as chemical energy without going through the intermediate step of first converting into electricity. By replacing the polyethylene (PE) separator as for conventional Li battery with a piezoelectric poly(vinylidene fluoride) (PVDF) film, the piezoelectric potential from the PVDF film as created by mechanical straining acts as a charge pump to drive Li ions to migrate from cathode to the anode accompanying with charging reactions at electrodes. This new approach can be applied to fabricating a self-charging power cell (SCPC) for sustainable driving micro/nano-systems and personal electronics.
    No preview · Chapter · Jan 2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: We demonstrate a pyroelectric nanogenerator (PENG) based on a lead zirconate titanate (PZT) film, which has a pyroelectric coefficient of about -80 nC/cm(2)K. For a temperature change of 45 K at a rate of 0.2 K/s, the output open-circuit voltage and short-circuit current density of the PENG reached 22 V and 171 nA/cm(2), respectively, corresponding to a maximum power density of 0.215 mW/cm(3). A detailed theory was developed for understanding the high output voltage of PENG. A single electrical output pulse can directly drive a liquid crystal display (LCD) for longer than 60 s. A Li-ion battery was charged by the PENG at different working frequencies, which was used to drive a green light-emitting diode (LED). The demonstrated PENG shows potential applications in wireless sensors.
    No preview · Article · Nov 2012 · Nano Letters
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Besides targeting at the worldwide energy needs at a large scope, we have been developing an area of nanoenergy, aiming at using nanotechnology to harvest the energy required for sustainable, independent and maintenance free operation of micro/nano-systems and mobile/portable electronics. As first reported in 2006, various nanogenerators (NGs) have been demonstrated using piezoelectric, triboelectric and pyroelectric effects. By using the energy from our living environment, our goal is to make self-powered system. The self-powering approaches developed here are a new paradigm in nanotechnology and green energy for truly achieving sustainable self-sufficient micro/nano-systems, which are of critical importance for sensing, medical science, infrastructure/environmental monitoring, defense technology and personal electronics.
    Full-text · Article · Dec 2012 · Materials Today
Show more