Lithium−sulfur (Li−S) batteries have been attracting great attention as promising rechargeable batteries because of their large specific capacity and high energy density. However, some technical problems still limit the commercialization value of Li− S batteries such as poor electrical conductivity, shuttle effects, and volume expansion. To overcome the aforementioned issues, Ndoped carbon composites were synthesized via a one-step hydrothermal method. To obtain different N-doping configurations, a carbon precursor was annealed at different heating rates, resulting in different N-containing properties. The cell with the most content of pyridinic-N delivered the highest initial discharge capacity of ∼1121 mAh g −1 , and the specific capacity still retained 605 mAh g −1 at 200 mA g −1 after 100 cycles. It was concluded that pyridinic-N has the most significant effect on immobilizing the soluble lithium polysulfides, which stabilized the cycle of Li−S batteries.

Antimony nanoparticle decorated reduced graphene oxide sheets with uniform distribution were synthesized as a new anode of aqueous chloride ion batteries in one step, which demonstrates a high capacity, and excellent reversibility and stability.

From the perspective of solutes, the "water-in-salt (WIS)" strategy is quite effective to expand the ESW of aqueous electrolytes. [16,17] Compared to the dilute solution, the super-concentrated solute can decrease the free water molecules by enhancing the interaction between the cations and anion. However, using super-concentrated solutes such as NaClO 4 will bring the disadvantages of low conductivity, explosion risk, and high toxicity, which compromises the environmental benefits, scalability, and specific energy of aqueous batteries. [18,19] In addition to the WIS, modulating solvents offers new insights to broaden the ESW, such as "molecular crowding" strategies, which successfully widen the ESW by using low-cost crowders and low salt concentration. However, the massive introduction of low dielectric constants solvents increases the probability of ion-pair formation and reduces the number of effective charge carriers. [20][21][22] Despite the weakened water activity by such strategies, the remarkably inhibited mobility of charge carriers results in a lowered ionic conductivity. Thus, the development of aqueous electrolytes with both extended ESW and high ionic conductivity remains challenging.According to the ionic conductivity equation (Scheme 1), the ionic conductivity can be affected by the carrier concentration (n i ), the ionic mobility (µ i ), and the valence order of ionic species (Z i ) (where e is the unit charge of electrons). [23] For the charge carrier concentration, solvents with high dielectric constants can dissolve more salt, thus can provide more cationsolvent dipoles in electrolytes. And for ionic mobility, as stated by the Stokes-Einstein relationship, decreasing the viscosity

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