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Lithium-sulfur batteries have not been widely commercialized due to issues with poor conductivity of the active material and the shuttle effect, both of which are effectively addressed in this study. The porous carbon CoNi-NC, derived from high-temperature carbonization of the cobalt–nickel metal–organic framework CoNi-ZIF, was utilized as the carbon substrate. It exhibits excellent specific surface area and a well-developed pore structure, thereby optimizing the conductivity and sulfur-loading capacity of the material. The incorporation of polar Bi2S3 effectively adsorbs polysulfides, retards the shuttle effect, and enhances the reaction kinetics of lithium-sulfur batteries. Electrochemical tests revealed that the CoNi-NC@Bi2S3 electrode achieved a specific discharge capacity of 1107 mAh/g at 0.1 C rate, demonstrating excellent rate capability. Moreover, the cathode material maintained a specific discharge capacity of 796.5 mAh/g after 200 cycles at 0.2 C, indicating robust cycling stability. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries have hindered industrialization due to their inherent defects. In this study, MXene and CNT composite Ni12P5 were used as cathode materials for lithium-sulfur batteries. MXene is known to have high specific surface area, while the CNT composite Ni12P5 has excellent electrical conductivity. The results show that MXene-CNT@ Ni12P5 composite can significantly improve the performance of lithium-sulfur batteries. The composite helps to mitigate the volume expansion and shuttle effect of the sulfur cathode, thereby improving the diffusion efficiency and cycling stability of the battery. In addition, the incorporation of the composite material enhances the electrical conductivity of the battery, reduces the secondary reaction with the electrolyte, and mitigates the deposition of polysulfides during lithium-ion charging and discharging, thereby further improving the lithium-ion diffusion efficiency. Therefore, this study presents a novel and convenient method to enhance the cathode material of lithium-sulfur batteries, which offers a broad prospect for its application in this field. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries have received lots of attention due to their high energy density and cheap material. The poor electrical conductivity and slow electrochemical kinetics of sulfur hinder their application. Here, we in situ grow Ni12P5 on carbon nanotube to prepare composites as sulfur host. Electrochemical tests show that Ni12P5 acts as an electrocatalyst in the lithium-sulfur batteries, initiating the oxidation of Li2S6 and Li2S4 at higher potentials, significantly improving the reaction kinetics during charging and discharging. The CNT@Ni12P5/S composite exhibited 1352 mAh/g initial discharge capacity at 0.1 C and a retention capacity of 85% after 100 cycles at 0.2 C. [ABSTRACT FROM AUTHOR]

A series of LiFePO4/C composites are prepared under the conditions of pH = 3, 5, 7, 8, 9 via biosynthesis method. The X-ray diffraction demonstrates that all of well-crystallized LiFePO4/C composites can be successfully prepared by adjusting the pH value. The images of scanning electron microscopy show that the structure and size of different samples have obvious changes. Besides, the LiFePO4/C composite prepared at the value of 8 delivers a best discharge capacity of 158.7 mAh/g at 0.1 C. The results show that the electrochemical performance of LiFePO4/C composites is governed by pH value. [ABSTRACT FROM AUTHOR]

The positive electrode material of the lithium-rich layered oxide has poor capability, and its cycle stability and rate characterizations have not been satisfactory. The lithium-rich cathode material Li1.2Mn0.54Ni0.13Co0.13O2 with different particle sizes was obtained by adjusting the pH by sol–gel method. The results show that the electrochemical performance of the material is optimal at pH = 9.0. It initial discharge capacity of 262.5 mAh/g at 0.1 C between 2.0 and 4.8 V. The high reversible discharge capacities is still of 161.0 and 133.7 mAh/g after 100 cycles at 0.5 C and 2 C, with a high capacity retention of 80.46% and 84.14%, respectively. This excellent electrochemical performance is attributed to smaller and uniform particles [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries received intense attention because of their high-energy density and inexpensive active material. However, the poor electrical conductivity of sulfur, shuttle effect, and slow electrochemical kinetics hinder their application. Herein, cobalt disulfides uniformly in situ grow on the surface of carbon nanotubes to prepare a three-dimensional carbon nanotubes-cobalt disulfide composite material as the sulfur host. The in situ growth cobalt disulfides on the carbon nanotube is confirmed to play the role of electrocatalyst, triggering the oxidation reaction of Li2S6 and Li2S4 at a higher potential, which promotes the conversion of Li2S6 to Li2S4 and Li2S4 to Li2S2, respectively, and significantly enhances the electrochemical reaction kinetics during the charge and discharge process. Particularly, the carbon nanotubes-cobalt disulfide-20 composite provides a suitable number of active sites for Li2S6 and Li2S4 and exerts an initial discharge capacity of 1253 mA h g−1 at 0.1 C and a retentive capacity of 84% after 200 cycles at 0.2 C. [ABSTRACT FROM AUTHOR]

Ti-doped barium ferrite nanoparticles were prepared by sol-gel method, and then preparing Ti-doped barium ferrite/CIP nanocomposites by physical blending method. Analysing the nanocomposites by X-ray diffraction (XRD) and vector network analyzer. We got the main conclusion: The nanocomposite reached its maximum reflection loss −30.71654 GHz with BaFe11.8Ti0.2O19/CIP = 1:0.3 and the coating thickness of 4.5 mm. The nanocomposites have a relatively wide absorbing band, and can absorb electromagnetic wave effectively within the multi-band frequency of 4.74-11.115 GHz and 11.71-14.43 GHz by controlling the amount of Ti-doping and coating thickness. The absorbing nanocomposites may have a broad application prospect. [ABSTRACT FROM AUTHOR]

The LiFePO4 material was successfully prepared by an effective and controllable hydrothermal method with the assistance of ethylene glycol (EG). Then, different carbon sources (glucose and carbon nanotubes (CNTs)) were used to synthesize LiFePO4/C and LiFePO4/CNTs composites and roundly investigated the performance of composites. The X-ray diffraction (XRD) showed that the composites had excellent crystallinity. Electrochemical performance tests demonstrated that the LiFePO4/CNTs composite exhibited the best discharge specific capacity. The special capacity was 154.6 mAh/g at 0.1C, which was higher than LiFePO4/C composite (144.8 mAh/g at 0.1C). The cycling performances of LiFePO4/CNTs composite showed better performances than LiFePO4/C composite at 1C and 10C. It can be attributed to a three-dimensional network structure of LiFePO4/CNTs that enhanced the electrochemical performance. [ABSTRACT FROM AUTHOR]