Yury Gogotsi, Drexel University
Flowable Capacitive and Pseudocapacitive Energy Storage
Written by Armin VahidMohammadi
Flowable energy storage devices have recently attracted a lot of attention because of the different advantages they can provide in large-scale energy storage and water deionization. Yury Gogotsi from Drexel University shed light on important aspects of the materials challenges for future flowable energy storage devices. He first summarized how energy is stored in batteries and supercapacitors by explaining the mechanisms of charge storage in electric double layer capacitors (EDLCs), pseudocapacitors, and batteries. Materials with pseudocapacitive properties are promising because the charge storage process happens fast enough in them that it is not diffusion-limited anymore. Gogotsi explained how this technology can be used in flowable applications and provide significant improvements. Flowable slurry of carbon suspended in a liquid electrolyte was given as an example to discuss the different effecting parameters in a flowable energy storage system. Gogotsi mentioned how we should move from the conventional electrode types to the suspension type electrodes. Some challenges in this field were also mentioned such as conductivity of slurry, loading of the material, dispersion, stability, rheological behavior, and electrochemical cell design. Gogotsi mainly focused on materials development for flow-based capacitive and pseudocapacitive systems. In the last part of his talk, he introduced their group’s findings on the application of two-dimensional (2D) transition metal carbides (MXenes) for flowable energy storage applications. MXenes, which were discovered back in 2011 at Drexel University, are a new family of 2D materials that exhibit very interesting and promising properties for different energy storage systems such as supercapacitors and batteries. He showed their preliminary results on excellent conductivity and the flow ability of MXene suspensions even with high loading of MXene flakes.