Flower-shaped NiCo2O4 hierarchical superstructures have been synthesized via a simple hydrothermal method with a post-annealing treatment. The single as-synthesized flower-shaped architecture is self-assembled from many nanosheets. When examined as a positive material for supercapacitors in a three-electrode configuration, the NiCo2O4 electrode shows typical faradaic redox properties consistent with battery-type materials and exhibits an excellent rate performance, with a 20-fold increase in the current density from 1 to 20 A g−1 (81.7% capacity retention of that at 1 A g−1).

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Activated carbon derived from lignite is investigated as the active electrode material in supercapacitors. ZnCl2 was used as excitation agent during preparation process. XRD, BET, SEM and electrochemical performance testing carried out to characterize the structure and properties of activated carbon. Electrochemical investigations indicate that the activated carbon (AC‐650°) shows the maximum specific capacitance of 207.5 F g−1 in 6 M KOH electrolytes at 0.5 A g−1. The activated carbon presents good cycle stability during 3,000 cycles at a fair current density of 5 A g−1 and capacity rate can reach 91 %, because of its specific surface area of 1024 m2 g−1.

Based on 5G wireless communication technology, this paper proposes a secure online banking payment scheme using a password algorithm and identity authentication+SMS verification code. We use the lightweight block cipher algorithm to construct a numeric permutation table. Then, we use the digital permutation table to perform the permutation encryption operation to obtain the digital ciphertext data. Finally, we connect 5G radiofrequency identification, identity authentication, and other modules to the trusted computing platform. The research found that the online banking security encryption algorithm proposed in the paper has the characteristics of high security and high efficiency.