New mineral can simultaneously convert movement, sunlight, and heat into electricity

Researchers from the University of Oulu in Finland discovered a mineral with a perovskite crystal structure and the properties necessary to simultaneously extract energy from numerous sources.

Movement, sunlight, and heat generated in a room all have the capability to power things like portable gadgets and wearable devices. While a typical perovskite (which is a family of minerals) has the ability to gather energy from one source, such as a change in temperature or pressure, the ability to collect energy from multiple sources is new. Those that can convert energy from pressure are referred to as piezoelectric material and those collecting energy from temperature are called pyroelectric.

If one member of the perovskite family collects energy one way, it may be used in conjunction with another family member that harnesses energy differently. Researchers have developed devices relying on multiple forms of energy which contain multiple materials, increasing their weight and overall size. The problem arises when one type of energy is not enough or not available, such as on a cloudy day or in a space where movement is limited. There can also be problems with material misalignment under certain conditions. 

KBNNO, the mineral under study, is a ferroelectric material and has dipoles which misalign under fluctuating temperatures. This causes an electric current. Electric charge can also collect based on the direction of the dipoles, and deformed material can further create issue by generating a current caused by certain regions either repelling or attracting a charge. 

Research had previously been done on KBNNO’s ferroelectric and photovoltaic properties, though they did not focus on pressure or temperature. Previous researchers also studied KBNNO at temperatures a few hundred degrees below freezing, making the results hard to replicate in a normal conditions or for normal use. 

The discoveries made by the University of Oulu’s research team are significant because they represent the first time anyone has looked at the mineral’s properties above room temperature and at the same time. And, although KBNNO can generate electricity from pressure and from heat, it isn’t as good as other minerals able to harness energy from those things independently. 
Researchers did discover, however, that KBNNO can be altered to improve pyroelectric and piezoelectric properties. 

Researchers continue to finetune the mineral’s composition and hope to build a prototype multi-energy-harvesting device within the year with a commercial device on the market within a few years, which could have important implications for energy sustainability and the Internet of Things. 

Source: Science News Journal