Carbon nanotubes composite embedded with silver nanoparticles as chloride storage electrode for high-capacity desalination batteries

Desalination battery (DB) is a new desalination technology with high desalination capacity, low energy consumption and mild operating conditions. However, its further development is greatly limited by the chloride storage electrode with high desalination capacity and good reversibility. Herein, Ag@10 %CNTs composite is developed as excellent chloride storage electrode, which delivers a high initial specific capacity of 120.0 mAh g⁻¹ at 100 mA g⁻¹, corresponding to a salt removal capacity of 250.4 mg-NaCl g⁻¹-composite if calculated based on the average charge efficiency of first ten cycles (i.e., 95.6%), and 41.3% is remained after 500 cycles. The excellent desalination capacity can be ascribed to the uniform distribution of small Ag particles, well-developed porous structure and good electric conductivity enabled by CNTs, resulting in the enhanced ions diffusion, conversion efficiency of AgCl to Ag and structural stability. Furthermore, the Ag@10 %CNTs is paired with NaTi₂(PO₄)₃ to construct the full desalination battery, delivering an initial capacity of 52.0 mAh g⁻¹ at 100 mA g⁻¹, and ∼27.5 mAh g⁻¹ is maintained after 300 cycles. This work provides new guidance for developing efficient chloride storage electrode for excellent desalination performance.