Insights into desalination battery concepts: current challenges and future perspectives

Water plays an essential role in the development of society. However, the worldwide supply of drinking water is becoming a challenge that needs to be addressed in the future. In this review we focus on new electrochemical technologies based on the concept of desalination batteries (DBs) and which feature different desalination approaches based on battery-like technologies reported to date. Here, we use the state-of-the-art knowledge and the current developments in materials and electrochemical engineering to promote an innovative approach in the search of strategies for increasing ion removal from salty electrolytes and energy storage capability. The motivation behind the present review is to reinforce the knowledge of each group of DB-based methods focusing on their figures of merit (FOM). Accordingly, it aims to address DBs as a promising technology to face water remediation at low energy consumption using the following key-aspects: (1) DB basis/concept, history and comparison to other electrochemical-based technologies; (2) DB-based concepts proposed in the literature, focusing on providing their FOM as the core of this review; (3) limitations and future challenges and opportunities. Moreover, discussions regarding charging-discharging mechanisms, cell designs and current issues on operational modes are also provided.