US EPA

7101928 

Journal Article 

Hybridizing energy conversion and storage in a mechanical-to-electrochemical process for self-charging power cell 

Xue, X; Wang, S; Guo, W; Zhang, Y; Wang, ZL; , 

2012 

1 

Nano Letters
ISSN: 1530-6984
EISSN: 1530-6992 

12 

9 

5048-5054 

English 

22876785 

10.1021/nl302879t 

WOS:000308576000105 

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.