Hydrogel and Its Composites for Pseudocapacitors

As the need for energy rises congruently with the global population, renewable alternatives are becoming a necessity. Traditional fossil-burning energy sources create large volumes of emissions. Meanwhile, common options for energy storage are non-recyclable and pollutive. In response to these failings, certain avenues of research are being performed. Material such as metal oxides, metal sulfides, and conductive polymers are promising candidates for electrocatalytic applications. This is due to the pseudocapacitive nature of these compounds, which allows for unique energy storage opportunities. Without a substrate, however, many of these materials would fail to operate as intended. Hydrogels, when used as either the precursor or the substrate, provide ample properties that improve electrocatalytic activities. The high porosity native to hydrogels and their analogs allow ions to interact with the electrocatalyst properly and more easily. Furthermore, the mechanical properties unique to hydrogels allow for flexible energy storage devices to be made.