The solubility parameters of four ionic liquids (ILs), 1-ethyl-3-methylimidazolium methyl sulfate ([EMIM]­[MeSO4]), 1-butyl-3-methylimidazolium methyl sulfate ([BMIM]­[MeSO4]), 1-hexyl-3-methylimidazolium methyl sulfate ([HMIM]­[MeSO4]), and 1-octyl-3-methylimidazolium methyl sulfate ([OMIM]­[MeSO4]), were estimated using two complementary methods. The first is an inverse gas chromatography (IGC) method, which determined the Hildebrand solubility parameters of four ILs based on a series of formulaic calculations. The second is the Hansen solubility sphere method, which determined the Hansen solubility parameters (HSPs) of the four ILs based on solubility testing of four ILs in 30 pure solvents. The results showed that the Hansen solubility sphere method provides higher values of the solubility parameters, while the IGC method presents lower values. In addition, the miscibilities of ILs in various solvents were evaluated by the method of IGC, and the results exhibit good agreement with those derived from the Hansen solubility sphere method. It is confirmed that the IGC and Hansen solubility sphere methods can be used to determine the solubility parameters of the ILs and were useful for solvent selection.

The rationally structural and compositional modulation endows electrode materials with unique physicochemical characteristics owing to their adjustable electronic properties. Herein, a phosphate-modified hierarchical nanoarray consisting of heterojunction with well-aligned cobalt...

Hybrid at either the mechanism or the device level can lead to a hybridization effect of the kinetics and electrochemical characteristic of a supercapacitor (SC). Herein, a heterostructured NiCo 2 S 4 /Co x Ni 1-x (OH) 2 battery-like cathode material was designed, with which the obtained sample accomplished the combination of excellent electronic and ionic conductivity so as to realize an enhanced faradaic redox storage process. Besides, a SC-type highly capacitive anode material of a N and S codoped porous carbon nanosheets (ACNS) was also fabricated, which exhibits great advantages in terms of its enlarged specific surface area, the ease of introducing pseudocapacitive reactions, and its physical structure. These features directly lead to significant improvements in the electric double-layer capacitor (EDLC)-type electrochemical properties of the carbon anode. The combination of an EDLC-type carbon anode with the redox-reaction-type cathode in a full cell device could potentially lead to a charge storage process that simultaneously integrates the electrophysical and electrochemical processes. For these reasons, the obtained solid-state hybrid SC delivers a wide voltage window of 1.6 V, a high specific capacity of 121.3 C g À 1 , and enhanced energy/power densities of 26.1 Wh kg À 1 /11 kW kg À 1 . The as-assembled device can maintain a high and stable capacity retention of 89.1 % for over 10 000 cycles. The developed hybrid assembly strategy and the electrode combination may provide design guidelines for designing other high-energy hybrid SCs.

The pursuit of promising precursors and simple preparation approaches boosts the development of sustainable carbon‐related energy systems. In this work, a relatively low‐cost and eco‐friendly ternary precursor system is presented for the fabrication of interconnected sheet‐structured porous carbon materials by the combination of template‐assisted pyrolysis and post‐activation. The variation of effect factors permitted the formation of tunable microstructures with multilevel pore channels, and the optimized sample (APC3‐700) with multiple desired properties (such as, large surface area, hierarchical interconnected pores, and nitrogen doping) was successfully synthesized. Due to the large electrode/electrolyte interface, short pathway for mass/charge transfer, high electrochemical activity, and low transport resistance, APC3‐700 proved to be a favorable material with high capacitance (225 F g−1 at 1 A g−1) and a high rate profile (remaining 91 % at 20 A g−1). In particular, the symmetrical supercapacitor assembled demonstrated a long cycle life with almost no capacitance decaying over 20 000 cycles. The method used may be employed for the widespread development of nanosheet‐connected carbon materials from different sources for efficient enhancement of energy storage.

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