Ultrafast, portable solar‐rechargeable batteries for the smart energy era

A collaborative team of ANFF-Q clients has developed an ultrafast and portable solar‐rechargeable battery with high efficiency, which can simultaneously harvest and store solar energy. These solar-rechargeable electric energy storage systems (SEESSs) will provide renewable power sources for smart grids, electric vehicles, portable electronics and the internet of things (IoTs).

The details of the device.

SEESSs—which can simultaneously harvest and store solar energy—are considered a promising next-generation renewable energy supply system. However, the practical application of current SEESSs is severely restricted by their limited ability to both store and deliver high power density.

A collaboration between the Wang, Shapter and Rowan Research Groups at the AIBN has resulted in the development of a new class of portable and highly efficient SEESS that uniquely integrates a perovskite solar module (PSM) and an aluminium-ion battery (AIB) directly on a bifunctional aluminum electrode without any external circuit. The results of this collaboration were published in Advanced Energy Materials.

The novel nanostructural design in the SEESS not only exhibits fast photo-charge/discharge rate (less than one minute) with high power density (above 5000 W kg−1), but also delivers a high energy density (above 43 Wh kg−1).

The power/energy density of available solar-rechargeable battery and our work.

“ANFF-Q facilities were very important in the development of this novel nanostructural design. The team used the E-beam at ANFF-Q to create the aluminium layer that is the bi-functional layer connecting both devices: it is the conductive layer of the photovoltaic and the anode of the AIB. Creating the aluminum layer at the correct thickness has significant impacts on the functionality of the SEESS. We also used the ANFF-Q sputtering system in the fabrication of the indium tin oxide (ITO) module, which is another important element of the integrated system,” said Dr Yuxiang Hu, lead author of the paper.

The team rationally matched the maximum power point voltage of PSM with AIB charging voltage to achieve an excellent solar-charging efficiency of 15.2% and a high photoelectric conversion and storage efficiency (PCSE) of 12.04%; this is among the best in all reported portable SEESSs.

Additionally this novel system demonstrates enhanced PCSE even as the light intensity decreases, making it immune from geographical location and climate limitations and effective for diverse practical applications. The team plan to continue developing this technology.

PCSE retention ratio of PSM-AIB illuminated by different light intensities (blue line). Red line is the various sunlight intensities at different times on a selected day at St Lucia Campus of the University of Queensland (inset figure).

“This work paves the way for the development of compact, integrated energy conversion/storage systems with high power and energy densities and overall energy utilisation efficiency. This technology is of particular importance for portable and self-powered devices. People will be able to use these electronic devices when they are camping or live far-away from the city,” said Dr Yuxiang Hu.

“We plan to continue utilising ANFF facilities to construct more smart devices for applications such as the indoor Internet of Things and seamless back-up power systems.”