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High-efficiency bifunctional catalysts with high energy conversion efficiency and high cycling performance are urgently needed for traditional zinc-air batteries (ZABs). Herein, a composite of highly active carbon layer covered Co4N cubes encapsulated in a nitrogen-doped porous carbon nanocage (Co4NC@NC) as a cathode catalyst was prepared by a hydrothermal acid-assisted strategy combined with subsequent calcination. The precursor is treated with carbon coating and calcination to obtain a double-carbon-layer-coated structure of Co4NC@NC. The inner carbon layer is tightly wrapped on the surface of the Co4N particles, and the outer carbon layer presents a porous structure. Co4NC@NC exhibits significantly enhanced electrocatalytic activities for ORR, OER and HER. In particular, the overpotential is only 166 mV for OER at a current density of 10 mA cm−2. Density functional theory calculations reveal that the synergistic effect between the N-doped graphite carbon layer and Co4N can improve the adsorption efficiency of intermediate products, accelerate the reaction kinetics, and reduce the free energy of rate determining steps. ZABs assembled with Co4NC@NC showed excellent stability during 1050 cycles at 5 mA cm−2. Furthermore, Co4NC@CN can also be used as an HER catalyst for overall water splitting, driven by Co4NC@CN-ZABs. The above results indicate that Co4NC@CN can be used as a high-performance three-function catalyst for ZABs and overall water splitting. [ABSTRACT FROM AUTHOR]

Cubic core–shell NiCoSx/CoS2 composite catalyst was successfully prepared on the basis of K3[Co(CN)6]. First, Ni2+ is substituted for K+ in K3[Co(CN)6]2 to prepare the binary metal ion precursor of Ni3[Co(CN)6]2. Afterward, coating Co(OH)2 on the surface of Ni3[Co(CN)6]2 could not only maintain the cubic structure of Prussian blue analogue but also build a composite interface between two phases. After the Ni3[Co(CN)6]2/Co(OH)2 precursor is sulfided, a porous NiCoSx/CoS2 composite catalyst material with a cubic structure is obtained. NiCoSx/CoS2 catalysts showed excellent oxygen evolution reactions and oxygen reduction reactions. The overpotential was only 310 mV to achieve a current density of 20 mA cm−2 and the half-wave potential can reach 0.80 V. During the exploration of the hydrogen evolution reaction, the catalyst exhibited 253 mV overpotential at 10 mA cm−2. When this catalyst was used in Zn–air batteries as the cathode, it showed excellent cycle stability (210 h) and small voltage gap (0.80 V) at 5 mA cm−2. Meanwhile, soft-pack flexible batteries assembled with NiCoSx/CoS2 can be charged and discharged stably at any bending angle. [ABSTRACT FROM AUTHOR]

Exploring the application of high‐efficiency bifunctional oxygen catalysts to rechargeable zinc‐air batteries has been a research hotspot in recent years. We succeeded in obtaining NiCo2NS with a hollow capsule structure through the self‐sacrificing template method, which has a larger specific surface area and can provide more active sites for electrocatalysis relative to his solid. The introduction of S can change the valence distribution of N and the electronic structure of the M−N bond, so that NiCo2NS exhibits excellent performance in the overpotential and stability of the oxygen reduction and oxygen evolution reactions. It shows an overpotential of 154 mV at 10 mA cm−2 and a half‐wave potential of 0.76 V. When used as a bi‐functional catalyst in zinc‐air batteries, it exhibits good stability within 400 h. The flexible battery assembled by NiCo2NS also shows excellent performance, and can be cycled stably for 20 h. The current maintains good stability when it is bent at different angles during the cycle. [ABSTRACT FROM AUTHOR]

In this paper, a synthesized novel strategy of varying predictive horizon-based model predictive control is proposed for the overtaking control of unmanned ground vehicle. The whole control strategy includes path planning and path tracking. First, the preferred path in presence of diverse constraints of states, inputs, and collision avoidance can be calculated using Gauss pseudospectral method where expected position, velocity, and attitude are provided. Correspondingly, the continuous optimal control problem is converted to discrete nonlinear programming. Second, model predictive control is developed for tracking the optimized path. Considering the effect of the predictive horizon and the Gauss points' distribution on tracking performance, the varying predictive horizon is introduced to improve the tracking accuracy in non-smooth path. By the varying predictive horizon-based model predictive control method, less computation burden and better control performance are achieved. For the difference between the mathematical expressions and the real unmanned ground vehicle dynamics, genetic algorithm is utilized to identify the parameters of tire model. Simulations in MATLAB and CarSim are both implemented to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Exploring the application of high-efficiency bifunctional oxygen catalysts to rechargeable zinc-air batteries has been a research hotspot in recent years. We succeeded in obtaining NiCo 2 NS with a hollow capsule structure through the self-sacrificing template method, which has a larger specific surface area and can provide more active sites for electrocatalysis relative to his solid. The introduction of S can change the valence distribution of N and the electronic structure of the M-N bond, so that NiCo 2 NS exhibits excellent performance in the overpotential and stability of the oxygen reduction and oxygen evolution reactions. It shows an overpotential of 154 mV at 10 mA cm -2 and a half-wave potential of 0.76 V. When used as a bi-functional catalyst in zinc-air batteries, it exhibits good stability within 400 h. The flexible battery assembled by NiCo 2 NS also shows excellent performance, and can be cycled stably for 20 h. The current maintains good stability when it is bent at different angles during the cycle., (© 2022 Wiley-VCH GmbH.)