Researchers Seok Woo Lee ‘09 Ph.D. ‘11 and Yi Cui from Stanford and Yuan Yang and Gang Chen from MIT have found a new battery technology that captures waste heat and converts it into electricity, a finding which was published in the journal Nature Communications last week.

In the past, scientists focused on thermoelectric devices, solid-state materials that can produce electricity from a temperature gradient, to harness waste heat.

However, these researchers found an alternative for low-temperature waste-heat conversion into electricity, utilizing a scientific principle known as the thermogalvanic effect which states that the voltage of a rechargeable battery is dependent on temperature.

According to Lee, the technique is to subject a battery to a four-step process: heating up, charging, cooling down and discharging.

“The results are very promising,” commented Peidong Yang, a professor of chemistry at the University of California, Berkeley. “By exploring the thermogalvanic effect, [the MIT and Stanford researchers] were able to convert low-grade heat to electricity with decent efficiency.”