Electric double layer capacitors (EDLCs) are made of activated carbon electrodes and store energy via electrostatic process in which charges are accumulated at the electrode/electrolyte interface through polarization. Thanks to the mechanism of energy storage, EDLCs offer the rapidest charging capacity and the lowest degradation, but they suffer from a low energy density[i].To overcome this situation, the pseudo-capacitors has been proposed and more recently incorporated to the market. As their name indicates, these devices resemblance the mechanism of EDCL but introduce pseudocapacitance to provide differential performance. Electrodes of these devices are made of transition metal oxides or electroactive polymer electrodes and store Energy through surface or bulk (pseudocapacitive) redox reactions, with a very fast charge transfer response, closer to EDLCs. However, while pseudo-capacitors store more energy than EDLCs, their widespread use has been hampered by their narrow electrochemical voltage window, which is the voltage range where the electrode materials are stable[ii]. The most intuitive approach to combine high energy and high-power density within a single device is to combine the different types of energy storage mechanisms. These brings us to the more novel proposed category of hybrid capacitors that are devices that show asymmetric electrodes exhibiting both significant double-layer capacitance and pseudocapacitance, such as lithium-ion capacitors.
During the last years, nanomaterials composed by the mixture of graphene and nanoparticles of metal oxides showed a promising alternative to the active carbons that still are the market standard in the field of supercaps. The inclusion of these nanomaterials family could provide more alternatives to the EDLCs and address the potential of pseudocapacitors and alternative Energy Storage configurations. However, the utilization of these nanomaterials into industrial applications seemed far to impact in the ES market at the degree of the potential expected from this approach.
Gnanomat owns a patented technology to develop and manufacture at industrial scale these nanomaterials family and lead the optimization of these nanomaterials to address industrial situations in the area of Energy Storage. In fact, Gnanomat has optimized its nanomaterials to provide remarkable outputs not just as a potential nanomaterial, but in a real and industrial context, that allow us to differentiate from our competitors and demonstrate its extraordinary potential in this applications.
Recently a Gnanomat nanomaterial graphene-based was optimized and tested in industrial asymmetric devices where one of the electrodes included this nanomaterial. Tests of this devices showed a. remarkable improvement of the cell Energy (around three times) when compared with a standard EDLC, without impairing the cyclability and the cell Power and confirmed the eligibility and industrial fitness of these materials and the technology underlying to its implementation in industrial applications. In addition, the versatility to manufacture a wide number of nanomaterials with optimized formulation, not only means a great potential of optimization of the devices, but also opens new possibilities to customize ES devices with specific electrochemical features by application, device, etc. Another feature to remark is that to address this milestone, Gnanomat utilized a green manufacturing method of synthesis, using nanomaterials lacking any toxicity and in a cell context using environmentally friendly electrolytes.
The industrial approach of Gnanomat rang the bell of industrial partners that are testing our nanomaterials in commercial devices.
The development degree of the Gnanomat nanomaterials,pre-industrial manufacturing capabilities, together with the performance in industrial prototypes and the versatility of these materials make Gnanomat a key partners of choice for the pseudocapacitor manufacturers.
[i] Simon, P. & Gogotsi, Y. Materials for electrochemical capacitors. Nat. Mater. 7, 845–854 (2008)