Energy storage, a technology that may capture and store energy produced at one time and/or certain place for use at a later time and/or another locations, is one of the most critical issues for current society. This may be achieved by multiple means such as chemical, thermal, electrochemical, electrical, magnetic, kinetic, and mechanical energy storage. The materials for energy storage applications can be metals, alloys, nonmetallic inorganic materials, organic materials, metal-organic frameworks, or various composites of the above ones.

Advanced scanning tools including scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic-force microscopy (AFM), scanning tunneling microscopy (STMs), and Raman spectroscopy are essential in observing morphology, characterizing the microstructure, and identifying specific physical and chemical properties in order to design innovative materials with controllable structures, understand the formation mechanism, clarify catalytic mechanism, and elucidate effect of designed parameters on energy storage properties. One example could be recent SEM with energy-dispersive X-ray spectroscopy and TEM with electron diffraction attachments used to study the evolution formation mechanism of a body-centered cubic structure Mg-Co metastable alloy, which is reported to show the lowest hydrogen absorption temperature to date.

The aim of this special issue is to publish high quality research papers as well as comprehensive review ones addressing latest and state-of-the-art topics from active researchers in these fields. A particular focus is analytic scanning techniques and novel applications of the microscopies in design, synthesis, and development of energy storage materials with outstanding performances.

Advanced analytic scanning techniques (SEM, TEM, STM, AFM, Raman, etc.) are adopted for characterization of the following.

Potential topics include but are not limited to the following:

• Hydrogen energy materials for hydrogen production, hydrogen storage, hydrogen delivery, and so forth.
• Materials for fuel cell applications (electrodes, electrolytes, membranes, electrolytes, catalysts, etc.)
• Lithium-ion battery materials (electrodes, catalysts, electrolytes, etc.)
• Super capacitors (electrodes, electrolytes, etc.)
• Other materials with outstanding properties for next-generation energy storage applications (thermoelectric materials, metal-air batteries, Na-S batteries, solar cells, heat storage, etc.)