Summary In this paper, nanosized Ni3Sn4 nanoparticles were synthesized by chemical reduction technique. A facile strategy is also developed to synthesize the yolk‐shell Ni3Sn4 nanoparticles decorated between the layers of multilayer graphene to obtain high‐capacity, long service life with comparable cost Li‐ion batteries. Ni3Sn4 nanoparticles in the form of yolk‐shell morphology were synthesized between 30 and 130 nm in size and homogeneously anchored on graphene layers as spacers preventing the layers merging after vacuum filtration. The characterization of the as‐synthesized composite electrodes was performed by scanning electron microscopy and X‐ray diffraction methods. As an anode electrode, yolk‐shell Ni3Sn4/graphene composite electrodes revealed a stable capacity of 324.5 mAh g−1 after 250 cycles, indicating that the composites might have a promising future application in Li‐ion batteries. The results have shown that unique yolk‐shell Ni3Sn4/graphene hybrid composite structure shows extraordinary electrochemical performance with superior reversible capacity and improved cyclic performance, indicating that the stacking of the active electrode nanoparticles between the graphene layers is a good method for maximum specific capacity outputs.

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Herein, silicon nanoparticles (nSi) are produced by magnesiothermic reduction methods. nSi are then obtained in the form of a 3D graphene aerogel (GA), prepared by a simple one‐step freeze‐drying process using L‐ascorbic acid. By a simple freeze‐drying process, nSi is neatly decorated between sheets of graphene. GA forms a conductive structure for nSi whose mechanical mesh acts as a buffer layer. This conductive structure greatly improves the structural integrity and conductivity of the anode material. Nanoparticles silicon/graphene aerogel (nSi/GA) nanocomposite is investigated by X‐ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. nSi/GA nanocomposite demonstrates a superior capacity of 550 mAh g−1 after 500th cycle. As a result, the nSi/GA anodes show improvement in cycling stability compared with pure nSi. Tests are conducted at different rate capability to measure the velocity characteristic and the resulting anode exhibits average specific discharge capacities of 1217, 976, 919, 825, 674, and 572 mAh g−1 at charge/discharge rates of C/20, C/10. C/5, 1C, 3C, and 5C, respectively. Benefiting from easy synthesis and excellent cyclic stability, nSi/GA are expected to play an important role in the lithium‐ion battery.

In this work, we introduce LiNi0.8Mn0.15Al0.05O2 (NMA), which is cobalt-free and has a high nickel content, and a conductive composite material to NMA by supporting it with a three-dimensional (3D) graphene aerogel (GA). With an easy freeze-drying approach, NMA nanoparticles are properly dispersed on graphene sheets, and GA creates a strong and conductive framework, significantly improving the structure and conductivity. The structure of the pure NMA and NMA/graphene aerogel (NMA/GA) composite was investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). XRD and FE-SEM analyses clearly indicated that ultrapure NMA structures are homogeneously dispersed among the GAs. In addition, the composite structure was examined using transmission electron microscopy (TEM) to determine the dispersion mechanisms. The electrochemical cycling performance of the pure NMA and NMA/GA composite was evaluated by rate capacitance, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The synthesized NMA/GA was able to provide 89.81% specific capacity retention after the 500th cycle at C/2. The average charge/discharge rates of the obtained cathode show good electrochemical results and exhibit capacities of 190.2,186.3, 185.2, 176.2, 161.2,142.6, and 188.5 mAh g–1 at C/20, C/10, C/5, C, 3C, 5C, and C/20, respectively. EIS data showed an improvement in the impedance of the composite containing GA. According to the results of the electrochemical tests, NMA nanoparticles formed a conductive network with its porous structure thanks to GA, formed a protective layer on the surface, prevented the side reactions between the cathode and the electrolyte, decreased the impedance of the cathode, and increased the redox kinetics. In addition, the changes in the structure were investigated in the NMA/GA composite cathode by XRD, FE-SEM, and Raman analyses at the end of the 50th, 250th, and 500th cycles. In summary, the NMA/GA cathode is expected to play an important role in lithium-ion batteries (LIBs) by taking advantage of its easy synthesis and excellent cycle stability.