Three-Dimensional Cobalt Hydroxide Hollow Cube/Vertical Nanosheets with High Desalination Capacity and Long-Term Performance Stability
Yuecheng Xiong,
Fei Yu,
Stefanie Arnold,
Lei Wang,
Volker Presser,
Yifan Ren,
Jie Ma
Affiliations
Yuecheng Xiong
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Research Center for Environmental Functional Materials, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
Fei Yu
College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
Stefanie Arnold
INM-Leibniz Institute for New Materials, 66123 Saarbrücken, Germany; Department of Materials Science and Engineering, Saarland University, 66123 Saarbrücken, Germany
Lei Wang
INM-Leibniz Institute for New Materials, 66123 Saarbrücken, Germany; Department of Materials Science and Engineering, Saarland University, 66123 Saarbrücken, Germany
Volker Presser
INM-Leibniz Institute for New Materials, 66123 Saarbrücken, Germany; Department of Materials Science and Engineering, Saarland University, 66123 Saarbrücken, Germany; Saarene-Saarland Center for Energy Materials and Sustainability, 66123 Saarbrücken, Germany
Yifan Ren
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Research Center for Environmental Functional Materials, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
Jie Ma
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Research Center for Environmental Functional Materials, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
Faradaic electrode materials have significantly improved the performance of membrane capacitive deionization, which offers an opportunity to produce freshwater from seawater or brackish water in an energy-efficient way. However, Faradaic materials hold the drawbacks of slow desalination rate due to the intrinsic low ion diffusion kinetics and inferior stability arising from the volume expansion during ion intercalation, impeding the engineering application of capacitive deionization. Herein, a pseudocapacitive material with hollow architecture was prepared via template-etching method, namely, cuboid cobalt hydroxide, with fast desalination rate (3.3 mg (NaCl)·g-1 (h-Co(OH)2)·min-1 at 100 mA·g-1) and outstanding stability (90% capacity retention after 100 cycles). The hollow structure enables swift ion transport inside the material and keeps the electrode intact by alleviating the stress induced from volume expansion during the ion capture process, which is corroborated well by in situ electrochemical dilatometry and finite element simulation. Additionally, benefiting from the elimination of unreacted bulk material and vertical cobalt hydroxide nanosheets on the exterior surface, the synthesized material provides a high desalination capacity (117±6 mg (NaCl)·g-1 (h-Co(OH)2) at 30 mA·g-1). This work provides a new strategy, constructing microscale hollow faradic configuration, to further boost the desalination performance of Faradaic materials.
