Spinel flowered-shaped MnCo2O4 nanocrystals for highly efficient capacitive desalination

• The spinel flower-shaped MnCo 2 O 4 nanocrystals have been synthesized. • The MnCo 2 O 4 possesses abundant redox couples of Mn 2+ /Mn 3+ and Co 2+ /Co 3+ . • The MnCo 2 O 4 cathode has realized high desalination capacity of 88.66 mg/g. In this work, the spinel MnCo 2 O 4 (MCO) nanocrystals have been prepared for high-performance capacitive deionization (CDI). The structure and properties of MCO can be tunneled by varying the annealing temperature from 500 to 700℃.The optimized MCO exhibits the unique flower-shaped structure, which provides abundant channels for ions diffusion. Meanwhile, the diverse valence state related to Mn and Co promotes the adsorption/desorption of Na + . As a result, the desalting capacity of MCO is 88.66 mg g −1 at 1.2 V in 1000 μS cm −1 NaCl solution.