Researchers at the University of Minnesota’s College of Science and Engineering have identified a novel alloy material, which transforms heat energy into electrical energy. This innovative energy conversion process could allow the production of eco-friendly electricity from waste heat sources.
According to the scientists, the alloy material could be utilized to generate electricity to charge a hybrid car’s battery by absorbing the waste heat released from the car’s exhaust.
The alloy material could also be used for capturing temperature variances in the sea as well as the rejected heat from power and industrial facilities to generate electricity. The researchers are continuing their efforts to commercialize the technology.
The head of the research team, Richard James, who serves as aerospace engineering and mechanics professor at University of Minnesota, commented that it is an ultimate sustainable technology to produce electricity, as it utilizes waste heat to generate electricity without CO2.
The researchers coupled elements at the atomic level to produce a multiferroic alloy material, Ni45Co5Mn40Sn10, which demonstrates superior electric, magnetic and elastic properties. The new alloy attains multiferroism through highly reversible phase transformation in which one solid converts into another solid. This phase transformation changes the alloy’s magnetic properties, which are manipulated in the energy conversion device.
During a lab test at the University of Minnesota, the Ni45Co5Mn40Sn10, originally a non-magnetic material, turned into a highly magnetic material due to a mild increase in temperature. When this phenomenon occurred, the alloy absorbed heat and generated electricity instantly in a surrounding coil. An important breakthrough made by the researchers is the efficient method to reduce hysteresis during phase transformations.