During the past 40 years, significant efforts have been focused on the development of aprotic lithium-ion batteries featuring higher energy density, while the development of their cousins, aqueous batteries, has lagged behind. However, this has changed within the last decade due to the new demand for different energy storage systems to aid in achieving a low-carbon society.The principal aim of this book is to present a comprehensive coverage of aqueous battery developments. The book covers:Fundamental electrochemistryTechnical developments and challenges in the fieldPrototypical systemsThis book will have wide appeal for both academics and industry professionals working in the fields of sustainable energy, batteries and electrochemistry.