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By incorporating copper sulfate (CuSO₄) particles into acrylonitrile butadiene rubber (NBR) followed by heat pressing, a novel vulcanization method is developed in rubber through the formation of coordination crosslinking. This method totally differs from traditional covalent or non-covalent vulcanization approaches of rubber. No other vulcanizing agent or additional additive is involved in this process. By analyzing the results of DMA, XPS and FT-IR, it is found that the crosslinking of (CuSO₄) particles filled NBR was induced by in situ coordination between nitrogen atoms of nitrile groups (–CN) and copper ions (Cu²⁺) from (CuSO₄). SEM and EDX results revealed the generation of a core ((CuSO₄) solid particle)-shell (adherent NBR) structure, which leads to a result that the crosslinked rubber has excellent mechanical properties. Moreover, poly(vinyl chloride) (PVC) and liquid acrylonitrile-butadiene rubber (LNBR) were used as mobilizer to improve the coordination crosslinking of (CuSO₄)/NBR. The addition of PVC or LNBR could lead to higher crosslink density and better mechanical properties of coordination vulcanizates. In addition, crystal water in (CuSO₄) played a positive role to coordination crosslinking of rubber because it decreased the metal point of (CuSO₄) and promoted the metal ionization.

A series of nickel sulfides derived from the hexagonal Ni-MOF are vulcanized through adjusting the hydrothermal time and the thiourea concentration. Among all the obtained nickel sulfides, one sample Ni-S2-3, which inherits the Ni-MOF’s morphology, shows the best electrochemical performance with a remarkable specific capacitance of 1128Fg${}^{-1}$ at 1Ag${}^{-1}$, a rate capacitance of 50% and a long cycle life of 74% retention after 5000 cycles. Furthermore, the asymmetrical supercapacitors (SCs) based on Ni-S2-3//AC exhibit a good supercapacitive performance with a maximum power density of 16.3Wh kg${}^{-1}$ at a power density of 800Wkg${}^{-1}$. All these results indicate that vulcanizing Ni-MOF is an effective way to fabricate a superior electrode material with excellent electrochemical performance for SCs.