Achieving high energy density and high power density with pseudocapacitive materials

Nanoporous carbon for electrochemical capacitive energy storage

“…Instead of collecting the total capacitance of the cell, the differential capacitances at both positive and negative electrodes during polarization, which reflect the contribution to EDL capacitance from the anions and cations, were used to understand the correlation between C/S and pore size. Importantly, the surface area accessible to anions and cations was also defined differently, with the cutoff pore size of 0.4 (S 40.4 ) and 0.6 (S 40.6 ) nm being selected for BF 4 À and TEA + , respectively, to take into account the difference in ion size. The pore sizes of d 25 and d 75 (representing the pore width at 25 and 75% of the total pore volume, respectively) were also added in complement to d 50 (the pore width at 50% of the total pore volume) to capture a more reliable picture of the porosity than the mean diameter.…”

“…2 By contrast, supercapacitors store the charge at the electrode/ electrolyte interface, via physical ion adsorption/desorption process, for electrochemical double-layer capacitors (EDLCs); through fast and non-diffusion limited faradaic reactions for pseudocapacitive materials. 3,4 These fast and highly reversible storage mechanisms make supercapacitors promising candidates for energy storage devices with high power density and a long cycling life, 5 which are nowadays used in a broad range of applications where high power delivery and/or uptake is needed, such as energy harvesting. 6,7 However, the energy density (B10 W h kg À1 for the best commercial devices) still hampers the spread of this technology over a wider range of applications.…”

MoS2/carbon composites prepared by ball-milling and pyrolysis for the high-rate and stable anode of lithium ion capacitors

“…The other is the construction of capacitive cathode and battery-type anode. 9,[13][14][15][16] In 2001, Amatucci et al had developed the system which consists of nano-Li 4 Ti 5 O 12 as the battery-type anode and N-doped activated carbon as the capacitor-type cathode. 17 However, on account of the different mechanisms of energy storage, the power and energy densities depends on the faradaic-type anode with sluggish reaction kinetics and the adsorption-type cathode with low capacity, respectively.…”

Fatsia Japonica-Derived Hierarchical Porous Carbon for Supercapacitors With High Energy Density and Long Cycle Life

“…Due to their high energy density, long cycle life, and fast discharge/charge characteristics, SCs bridge the gap between conventional electrolytic capacitors and LIBs. Based on their energy storage mechanism, supercapacitors can be divided into two categories: electric double-layer capacitors (EDLC) and pseudo-capacitors (Choi et al, 2019;Zhao et al, 2019b). However, the key to the electrochemical performance of SCs lies in the choice and design of electrode materials.…”