Pseudocapacitive materials can synergistically achieve the aim of both high energy as well as high-power density. However, the cycling stability is usually not satisfactory. To overcome this drawback, a carbon coating method is employed. Herein, we report a simple one-step method for the fabrication of Co 3 V 2 O 8 @C composite structures. Such Co 3 V 2 O 8 @C anode materials exhibit superior long cycle performance, which can deliver a discharge capacity of ∼835 mAh g −1 at a current density of 4.0 A g −1 for more than 500 cycles with a capacity retention of ∼100%. Moreover, a notable rate performance of 808, 712, 307, and 101 mAh g −1 under current densities of 5, 10, 20, and 30 A g −1 is also achieved, respectively. The experimental data clearly demonstrate that the intriguing electrochemical properties can be ascribed to the synergistic effects of pseudocapacity and carbon coating. To be specific, the pseudocapacity ensures the rate performance, while carbon coating ensures the cycling performance. This may pave the way for the development of lithium-ion batteries with high power and energy density. Moreover, this synthetic strategy can be an instructive precedent for fabricating ternary metal oxides with excellent electrochemical performance.

WO3 nanobundles and nanorods were prepared using a facile hydrothermal method. The X-ray diffraction pattern confirms that the obtained samples are pure hexagonal WO3. Transmission electron microscope images detected the gap between the different nanowires that made up the nanobundles and nanorods. As the anode materials of lithium-ion batteries, the formed WO3 nanobundles and WO3 nanorods deliver an initial discharge capacity of 883.5 and 971.6 mA h g−1, respectively. Both WO3 nanostructures deliver excellent capacity retention upon extended cycling. At a current density of 500 mA g−1, the reversible capacities of WO3 nanobundle and WO3 nanorod electrodes are 444.0 and 472.3 mA h g−1, respectively, after 60 cycles.

Tin dioxide (SnO2) has been the focus of attention in recent years owing to its high theoretical capacity (1494 mAh g−1). However, the application of SnO2 has been greatly restricted because of the huge volume change during charge/discharge process and poor electrical conductivity. In this paper, a composite material composed of SnO2 and S, N co-doped carbon (SnO2@SNC) was prepared by a simple solid-state reaction. The as-prepared SnO2@SNC composite structures show enhanced lithium storage capacity as compared to pristine SnO2. Even after cycling for 1000 times, the as-synthesized SnO2@SNC can still deliver a discharge capacity of 600 mAh g−1 (current density: 2 A g−1). The improved electrochemical performance could be attributed to the enhanced electric conductivity of the electrode. The introduction of carbon could effectively improve the reversibility of the reaction, which will suppress the capacity fading resulting from the conversion process.

A rationally designed strategy was employed for the preparation of the VN@C with hollow structure using ZIF-8 polyhedra as the sacrificial templates. Meanwhile, ZIF-8 also plays the role of both...

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