Flat substrate supercapacitor without substrate and fixed shape developed by Dalian Institute of Chemical Industry

[ Instrument Network Instrument R & D ] Recently, the team of Wu Zhongshuai, a researcher of the two-dimensional materials and energy device research group of the Dalian Institute of Chemical Physics, the Chinese Academy of Sciences, and Fu Qiang, a researcher of the nano and interface catalysis research team, have developed a new device assembly method A planar patterned microelectrode was wrapped in a chemically cross-linked graphene oxide-polyvinyl alcohol-based hydrogel electrolyte, and a new concept micro-capacitor without a substrate and shape was successfully constructed.

Two adjacent conductors are sandwiched by a layer of non-conductive insulating medium to form a capacitor. When a voltage is applied between two plates of a capacitor, the capacitor stores charge. The capacitance of a capacitor is numerically equal to the ratio of the amount of charge on one conductive electrode plate to the voltage between two electrode plates. The basic unit of capacitance of a capacitor is farad (F). The capacitor element is usually represented by the letter C in the circuit diagram.

Micro supercapacitor is a very important high-power miniature energy storage device. However, due to various factors such as the introduction of the substrate, the poor compatibility between the electrode / electrolyte and the substrate, the complicated packaging process, etc., the device has a single fixed shape and mechanical flexibility. Poor, low energy density, it is difficult to meet the application scenario requirements of specific microsystems with high requirements on space and flexibility.

Capacitors play an important role in circuits such as tuning, bypassing, coupling, and filtering. It is used in the tuning circuit of the transistor radio, and it is also used in the coupling circuit and bypass circuit of the color TV. With the rapid development of electronic information technology, the upgrading of digital electronic products is getting faster and faster. The production and sales of consumer electronics products, mainly flat panel televisions (LCD and PDP), notebook computers, digital cameras and other products, continue to increase, driving the Capacitor industry grows.

Recently, researchers at the Dalian Institute of Chemical Research and Development have developed a new device assembly method of "microelectrodes integrated in a gel electrolyte to prepare an integrated film", which wraps two-dimensional materials (such as MXene, graphene) -based planar patterned microelectrodes on In the chemically cross-linked polyvinyl alcohol-based hydrogel electrolyte film containing graphene oxide, a micro-capacitor without a base and a fixed shape based on the new concept of "microelectrode-electrolyte integrated film" was successfully constructed.

In fact, graphene originally exists in nature, but it is difficult to peel off the single-layer structure. One layer of graphene is graphite, and 1 millimeter thick graphite contains approximately 3 million layers of graphene. Gently scratching the pencil over the paper, the marks left may be several layers or even just one layer of graphene.

In 2004, two scientists at the University of Manchester, Andre Geim and Konstantin Novoselov, discovered that they could get thinner and thinner in a very simple way. Graphite flakes. They peeled the graphite sheet from the highly oriented pyrolytic graphite, then glued both sides of the sheet to a special tape, and tore off the tape, the graphite sheet could be divided into two. They continued to do this, and the sheets became thinner and thinner. In the end, they got a sheet made of only one layer of carbon atoms, which is graphene.

The device has ultra-thin device thickness (37 μm), ultra-flexibility, high area capacity (40.8 mF / cm2), and high integration. Especially under various deformation states such as bending, folding, twisting, and wrinkling, the miniature supercapacitor still maintains the original high electrochemical performance. For example, the highly integrated 9 series graphene-based miniature supercapacitor modules, under the condition of severe distortion (whole volume of the device from 0.11 cm3 to 0.01 cm3), the whole module still has excellent electrochemical consistency, Stable operation at a voltage of V. This work provides a universal method and a new design strategy for the development of new micro-energy storage devices without substrates and fixed shapes.