TheInstitute of Advanced Materials and Nanodevicesis engaged in making progress onnanogenerators. Recently, young teachers including Gu Long, Liu Jinmei, Cui Nuanyang and Xu Qi, under the guidance of Professor Qin Yong, successfully designed and fabricated a kind of piezoelectric nanogenerator which could greatly improve the output current density.

With the rapid development ofportable electronic devices, implantable medical devices andwireless sensor networks, problems including limited battery capacity and life and difficult replacement in traditional energy supply has become an increasingly problem.So it is imperative to develop sustainable energy which is portable and distributed to provide power for distributed electronic devices. To solve this problem, Academician Wang Zhonglin’s research team put forward a new energy harvest technology, piezoelectric nanogenerator (PENG). PENG can convertmechanical energy wildly existed in its surroundings such as mechanical vibration, acoustic wave, wind energy and bio mechanical energy, into electricity.Compared with electromagnetic power generation technology, PENG is more light, cheap, and effective in harvestinglow-frequencyenergy. PENG has receivesd attention across the world. This technology provides a new way to develop sustainable and stablemicrosource.

Up to now,lots of work has been done to improve the PENG’s output current, choosing materials with high piezoelectric property, such as BaTiO_3,PbZr_0.52Ti_0.48O_36,and designing innovative device structures to realize lateral, radial or vertical integration of individual piezoelectric nanomaterials. Its output voltage has been raised to hundreds of volts which are high enough for most electronic devices in our daily life, but the output current is still quite small, which has been the bottleneck of PENG’s development. Increasing PENG’s current density is still the key challenge.

In the research, under the guidance of Professor Qin Yong, young teachers including Gu Long, Liu Jinmei worked hard and successfully developed apiezoelectric nanogenerator with three-dimensional intercalation electrode according to the decisive relationship between Maxwell displacement current and PENG’s output current. By creating many boundary interfaces inside the piezoelectric material, the amount of surface polarization charges is multiplied, and the displacement currents induced by surface polarization charges are superposed, resulting in an increased current density. The maximum output current reaches 329 μA, and the corresponding current density is 290 μA cm⁻², which is 1.93 times the record value of PENG (150 μA cm⁻²⁾ and 1.61 times the record value of TENG (180 μA cm⁻²). The surface charge density is 1690 μC m⁻², which is 1.35 times the record value of TENG. This work will promote the development of nanogenerator and has great potential in realizing self-powered electronic systems.

Figure 1 Schematics and simulation results of the IENG

a. Basic structure and working principle of the three-dimensional intercalation electrode. b. Distribution of piezoelectric potential in different units when the same piezoelectric layer model is divided into 1, 2, 3, 4, 6 and 12 units by different pairs of intercalation electrode. c. The corresponding output charge density and output voltage by different units.

Figure 2 Output performance of IENG

a, b.The rectified current and voltage signals. c. 100 red LEDs are instantaneously lighted up by the IENG without storage process. d. the position of the current density of IENG. e. Charging curve for a 1 μF capacitor, and the corresponding charging rate is 405 nC per cycle. f. Charge density of IENG and selected representatives.

Relative introduction:

This research is published inNature Communications.Link:

http://www.nature.com/articles/s41467-020-14846-4。

Institute of Advanced Materials and Nanodevices was officially established in 2017, including 11 teachers, 1 professor, 1 visiting professor, 1 associate professor, 8 lecturers. To meet the demand of clean energy and sustainable development of electricity, research team of the institute focused onmaterials science in fields of new energy storage and conversion, concerned about scientific and technological problems of application of energy materials in functional devices. The research team intensively carried out researches in fields of new nanogenerator materials and devices, solar batteries, piezoelectric electronics, photoelectrocatalysis,lithium-ionbatteries. In recent years, the Institute has made several breakthroughs in nanogenerator and other fields, and the achievements have been highly recognized by international and domestic experts.