From fulfilling individual needs for the small-scale storage of electricity in household gadgets to providing larger-scale storage capacities in electric vehicles, electrochemical energy storage (EES) devices have become an intrinsic part of human activities. The global demand for EES systems has led to an increase in research into the development of materials and devices, which are cheaper, safer, more durable, and higher-performing both per unit mass and per unit volume. Also, recyclability is getting more and more critical for the sustainable use of EES materials in the near future. Accordingly, this section is devoted to recent advances and progress in the development of energy storage materials, cell design & manufacturing, management & operation technologies, recycling strategies & technologies, and analytical techniques as well as elucidating fundamental electrochemical mechanisms and reactions.