Empa Researchers Develop Improved Graphene-Based Supercapacitors

(CONNECT) Empa researchers from the Functional Thin Film Solution Processing group are developing graphene-based supercapacitors that achieve a higher energy density than conventional activated carbon models. According to a press release, the aim is to transfer these improved supercapacitors with high conductivity, selectively adjustable pore size and large surface area to industrial series production. Such capacitors are used as energy storage devices in areas such as electric cars, wind turbines and industrial machinery.

Supercapacitors consist of two electrodes surrounded by a liquid electrolyte. During discharge, the electrolyte transports the charge carriers (ions) from one electrode to the other. The more ions that can dock onto the surface of the electrode, the higher the energy density of the supercapacitor. Conventional models use activated carbon as the electrode material, which, unlike graphene, has a low conductivity, resulting in a lower storage capacity. The porous surface of the activated carbon is further impaired by the use of binding agents in industrial production.

The Empa researchers are therefore using a proprietary process to process pure graphene cost-effectively and efficiently into a gel-like printable ink for industrial electrode production. The mixture of two types of graphene makes it possible to specifically influence the pore size between the graphene layers in the ink. "If we adjust the pore size of the electrode to the size of the ions in the electrolyte, the energy density of the supercapacitor increases dramatically," says Sina Azad, postdoctoral researcher in Empa's Functional Polymers Laboratory, in the press release.

By the end of the project in 2028, the researchers also want to produce the new electrodes themselves and install them in functioning supercapacitor prototypes. "At the end of the project, we want to bring our technology to the market, either with industrial partners or via our own spin-off," says Jakob Heier, Head of the Functional Thin Film Solution Processing research group. ce/yes