In situ synthesis of ultrasmall NaTi2(PO4)3 nanocube decorated carbon nanofiber network enables ultrafast and superstable rocking-chair capacitive deionization
In situ synthesis of ultrasmall NaTi2(PO4)3 nanocube decorated carbon nanofiber network enables ultrafast and superstable rocking-chair capacitive deionization
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DOI：
10.1016/j.cej.2023.142394
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发表时间：
2023-03
影响因子：
15.1
通讯作者：
Kai Wang;Yong Liu;Xingtao Xu;Yanling Jiao;L. Pan
中科院分区：
文献类型：
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作者：
Kai Wang;Yong Liu;Xingtao Xu;Yanling Jiao;L. Pan
法拉第电容式去离子技术(CDI)作为传统电容式去离子技术的重要衍生产品，在海水淡化领域受到了广泛的关注。然而，从其固有的离子存储机制来看，法拉第CDI存在着离子存储容量不平衡、脱盐率低、循环稳定性差等严重问题，极大地制约了其进一步发展。在这里，我们提出了一种创新的策略，使用碳纳米纤维增强的NaTi2(PO4)3(eCNF/NTP)作为核心材料(用于捕获Na+)，并进一步将其与合理的摇椅电容去离子(RCDI)电池架构相结合。值得注意的是，由于eCNF/NTP独特的三维网络结构，不仅提供了足够的氧化还原活化中心，还提供了刚性的网络结构，防止了循环过程中的潜在聚集，以及合理的RCDI对称单元结构，避免了正负离子存储容量的失衡，因此配备eCNF/NTP电极的RCDI系统表现出优异的淡化性能(脱盐能力：168.2 mg/g−1；脱盐率：0.46 mg/g−1s−1)，并且具有出色的循环稳定性(80次循环后，脱盐能力仅下降6%)。这项工作很有趣，因为它展示了精致的材料设计和合理化的单元结构在解决CDI瓶颈问题方面的关键重要性，这可能会对其他高性能海水淡化系统的未来发展有所启发。
Faradic-based capacitive deionization (CDI), as an important derivative of conventional CDI, has received wide attention in the desalination community. Yet, oriented from its intrinsic ion storage mechanism, faradic-based CDI has been plagued by several serious issues (e.g., imbalanced ion storage capacity, low desalination rate, and poor cycling stability), which greatly constrained its further development. Herein, we put forward an innovative strategy by using carbon nanofiber-reinforced NaTi2(PO4)3(eCNF/NTP) as the core material (for Na+-capturing) and further coupling it with rational rocking-chair capacitive deionization (RCDI) cell architecture. Of note, owing to the unique 3D network structure of eCNF/NTP that not only provides sufficient redox-activate sites but also offers a rigid network structure to prevent the potential aggregation during cycling, as well as the rational RCDI symmetric cell architecture to avoid the imbalanced cation and anion storage capacity, the RCDI system equipping with eCNF/NTP electrode displays an excellent desalination performance (desalination capacity: 168.2 mg g−1; desalination rate: 0.46 mg g−1s−1) with outstanding cycling stability (only 6 % desalination capacity degradation after 80 cycles). This work is interesting because it showcases the critical importance of both delicate material design and rationalized cell architecture in addressing the bottleneck issue of CDI, which could shed light on the future development of other high-performance desalination systems.