From desalination to electrochemical mining: A global bibliometric and critical review of selective CDI technologies

As pressures on the water-energy-resource nexus intensify, capacitive deionization (CDI) is increasingly evolving from a conventional desalination technology into a platform for selective resource recovery. However, a systematic understanding of its developmental trajectory and research transformation remains limited. This study presents a comprehensive bibliometric and visualization analysis of global research on selective CDI technologies from 2007 to 2026, based on 1353 publications analyzed using CiteSpace and VOSviewer. The results reveal a rapidly expanding research field with an increasingly structured global collaboration landscape. More importantly, the intellectual evolution of the field reflects a clear paradigm shift from desalination-oriented carbon-based systems toward selective ion separation and resource recovery. This transition is accompanied by a corresponding transformation in the underlying knowledge base, moving from electric double-layer mechanisms to battery-inspired electrochemical processes. This study provides a data-driven perspective on the evolution of selective CDI technologies and offers strategic insights into their transition from desalination systems to low-carbon electrochemical resource recovery platforms.