Kim, Kijae Ando, Yasunobu Sugahara, Akira Ko, Seongjae Yamada, Yuki Otani, Minoru Okubo, Masashi Yamada, Atsuo Dense Charge Accumulation in MXene with a Hydrate-Melt Electrolyte Electrochemical double-layer (EDL) capacitors operating at high charge/discharge rates are an important class of electrochemical energy storage devices. Aqueous EDL capacitors show great potential for use as inexpensive devices with much higher power; however, their energy density is severely limited by the narrow electrochemical window of water (1.23 V) and the small specific capacity of the electrodes. Here, we develop a high-voltage aqueous supercapacitor based on a highly concentrated Li<sup>+</sup> aqueous electrolyte (hydrate melt) and a two-dimensional titanium carbide MXene electrode. Experimental and theoretical analyses reveal the existence of dense hydrated Li<sup>+</sup> in the interlayer space of the deeply charged MXene, which is realized by the wide electrochemical window of a hydrate-melt electrolyte. The hydrate-melt electrolyte together with the large-capacitance MXene Ti<sub>2</sub>CT<sub><i>x</i></sub> improves the performance of an aqueous lithium-ion supercapacitor, offering a promising strategy for advanced aqueous capacitors. Hydrate-Melt Electrolyte Electrochemical double-layer;Dense Charge Accumulation;large-capacitance MXene Ti 2 CT x;Aqueous EDL capacitors show;supercapacitor;hydrate-melt electrolyte;Li;titanium carbide MXene electrode;electrochemical window;electrochemical energy storage devices 2019-06-11
    https://acs.figshare.com/articles/journal_contribution/Dense_Charge_Accumulation_in_MXene_with_a_Hydrate-Melt_Electrolyte/8313920
10.1021/acs.chemmater.9b01334.s001