The unique layered morphology of van der Waals (vdW) heterostructures give rise to a blended set of electrochemical properties from the 2D sheet components. Herein an overview of their potential in energy storage systems in place of precious metals is conducted. The most recent progress on vdW electrocatalysis covering the last three years of research is evaluated, with an emphasis on their catalytic activity towards the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). This analysis is conducted in pair with the most active Pt-based commercial catalyst currently utilized in energy systems that rely on the above-listed electrochemistry (metal–air battery, fuel cells, and water electrolyzers). Based on current progress in HER catalysis that employs vdW materials, several recommendations can be stated. First, stacking of the two types vdW materials, with one being graphene or its doped derivatives, results in significantly improved HER activity. The second important recommendation is to take advantage of an electronic coupling when stacking 2D materials with the metallic surface. This significantly reduces the face-to-face contact resistance and thus improves the electron transfer from the metallic surface to the vdW catalytic plane. A dual advantage can be achieved from combining the vdW heterostructure with metals containing an excess of d electrons (e.g., gold). Despite these recent and promising discoveries, more studies are needed to solve the complexity of the mechanism of HER reaction, in particular with respect to the electron coupling effects (metal/vdW combinations). In addition, more affordable synthetic pathways allowing for a well-controlled confined HER catalysis are emerging areas.

Herein, the chemical compatibility of the hydrogel electrolyte in highly alkaline pH was evaluated. Through simple experiments, we demonstrated that the frequently used polymer compound, acrylamide, is not stable at a high pH. The addition of glycerol as a cryoprotectant in highly alkaline hydrogels was also problematic due to the possible base‐initiated decomposition of glycerol to polyglycerols. Hence, a quick and simple one‐pot synthesis of highly alkaline potassium poly(acrylate) hydrogel with 1 vol % glycerol was proposed. The ionic conductivities of the hydrogel are 46.48 mS/cm and 8.67 mS/cm at 22 and −23 °C, respectively. One important benefit from the addition of the cryoprotectant is that the hydrogel sustained its mechanical features at temperatures as low as −80 °C. We also reported here for the first time the diffusion coefficients (D at ∼10−8 cm2/s), ionic mobilities (μ at ∼10−7 cm2/Vs), and ion density (n at ∼10−7 cm−3) of the hydrogel electrolyte used in flexible alkaline batteries.

Invited for this issue's Front Cover is the group of Prof. Anna Ignaszak from the University of New Brunswick (Canada). The cover picture shows the structure of a leakage‐free polymer electrolyte that sustains its ionic conductivity and mechanical resilience at extremely cold temperature. Read the full text of the Research Article at 10.1002/celc.202300113.