# Capacitive Deionization -- defining a class of desalination technologies

**Authors:** P. M. Biesheuvel, M. Z. Bazant, R. D. Cusick, T. A. Hatton, K. B. Hatzell, M. C. Hatzell, P. Liang, S. Lin, S. Porada, J. G. Santiago, K. C. Smith, M. Stadermann, X. Su, X. Sun, T. D. Waite, A. van der Wal, J. Yoon, R. Zhao, L. Zou, M. E. Suss  
**arXiv:** [1709.05925](https://arxiv.org/abs/1709.05925)  
**Date:** 2017-07-18  
**Summary page:** https://www.summarizepaper.com/en/paper/1709.05925v1/

## Key points

- Capacitive deionization (CDI) is an important technology class for water desalination
- CDI involves electrically driven removal of ions from a feed stream, storage in an electrode through ion electrosorption, and release in charge/discharge cycles
- CDI has low energy consumption, high efficiency, and can operate at low pressures
- CDI systems have been shown to effectively remove various types of ions from aqueous solutions such as seawater or brackish water
- Grouping all CDI methods under one technology class allows for easier comparison between different technologies within this class
- The study emphasizes the importance of capacitive deionization as a viable technology for water desalination and highlights its potential for future development and improvement.

## Summary

In recent years, the field of water desalination has seen a surge in attention towards capacitive deionization (CDI), which can now be considered as an important technology class alongside reverse osmosis and electrodialysis. These methods involve electrically driven removal of ions from a feed stream, storage in an electrode through ion electrosorption, and release in charge/discharge cycles. By grouping all these methods under the technology class of CDI, it is possible to treat evolving new technologies in standardized terms and compare them to other technologies in the same class. A recent study by P.M. Biesheuvel et al., titled "Capacitive Deionization -- defining a class of desalination technologies," delves deeper into this topic. The study highlights how CDI has become an important technology for water desalination due to its low energy consumption, high efficiency, and ability to operate at low pressures. Additionally, CDI systems have been shown to effectively remove various types of ions from aqueous solutions such as seawater or brackish water. The authors note that while there are variations among CDI systems, they all rely on electrostatic forces between charged electrodes and ions in solution for their operation. Furthermore, they discuss how grouping these systems under the umbrella term "CDI" allows for easier comparison between different technologies within this class. Overall, this study emphasizes the importance of capacitive deionization as a viable technology for water desalination and highlights its potential for future development and improvement.