Self-charging cell directly converts and stores energy

They claim that, by eliminating the need to convert mechanical energy to electrical energy for charging a battery, the new hybrid generator storage cell utilises mechanical energy more efficiently than systems using separate generators and batteries.

Central to the system is a piezoelectric membrane that drives lithium ions from one side of the cell to the other when the membrane is deformed by mechanical stress.

According to a statement, the lithium ions driven through the polarised membrane by the piezoelectric potential are directly stored as chemical energy using an electrochemical process.

By harnessing a compressive force, the power cell generates enough current to power a small calculator.

A hybrid power cell the size of a conventional coin battery can power small electronic devices — and could have military applications for soldiers who might one day recharge battery-powered equipment as they walk.

‘People are accustomed to considering electrical generation and storage as two separate operations done in two separate units,’ said Zhong Lin Wang, a Regents professor in the School of Materials Science and Engineering at GATECH. ‘We have put them together in a single hybrid unit to create a self-charging power cell, demonstrating a new technique for charge conversion and storage in one integrated unit.’