Si/SiO x Nanoparticles Embedded in a Conductive and Durable Carbon Nanoflake Matrix as an Efficient Anode for Lithium‐Ion Batteries

Hierarchical hollow porous structures of nickel-doped λ-MnO2 anodes for Li-ion energy storage systems

Metal oxides with hollow porous structures are attractive and promising anode candidates for Li-ion batteries due to their high surface area, high loading capacity, and low density. In this work, hierarchical hollow porous structures of nickel (Ni)-doped λ-MnO2 were prepared via a facile, and cost-effective approach, where different amounts of Ni were introduced into MnO2 structures to tailor their physical and chemical properties. When the prepared Ni-doped MnO2 hollow structures were studied as anode materials for Li-ion batteries, the electrode showed excellent electrochemical properties, such as stable cyclability and admirable rate capability. Moreover, Ni doping significantly enhances the diffusion properties of the active materials. The material was also investigated as an anode in another high power and energy Li-ion storage device, namely, a Li-ion hybrid capacitor, which exhibited excellent comprehensive electrochemical performance in terms of good specific cell capacity of 25 mA h g-1 at a high current density of 5 A g-1 and achieved a maximum power density of 29 W kg-1 (with energy density of 30 W h kg-1) with a long cycle life. These results indicate that the Ni-doped MnO2 is suitable for application as an anode material and give considerable insight into future Li-energy storage applications.

Cellulose-based bionanocomposites in energy storage applications-A review

The growing demand for energy and environmental issues are the main concern for the sustainable development of modern society. Replacing toxic and expensive materials with inexpensive and biodegradable biomaterials is the main challenge for researchers. Nanocomposites are of the utmost consideration for their application in energy storage devices because of their specific electrochemical properties. Cellulose-based bionanocomposites have added a new dimension to this field since these are developed from available renewable biomaterials. Studies on developing electrodes, separators, collectors, and electrolytes for the batteries have been conducted based on these composites rigorously. Electrodes and separators made of these composites for the supercapacitors have also been investigated. Researchers have used a wide range of micro- and nano-structural cellulose along with nanostructured inorganic materials to produce cellulose-based bionanocomposites for energy devices, i.e., supercapacitors and batteries. The presence of cellulosic materials enhances the loading capacity of active materials and uniform porous structure in the electrode matrix. Thus, it has shown improved electrochemical properties. Therefore, these can help to develop biodegradable, lightweight, malleable, and strong energy storage devices. In this review article, the manufacturing process, properties, applications, and possible opportunities of cellulose-based bionanocomposites in energy storage devices have been emphasized. Its challenges and opportunities have also been discussed.

Metal (Cu/Fe/Mn)-Doped Silicon/Graphite Composite as a Cost-Effective Anode for Li-Ion Batteries

Silicon is a worthy substitute anode material for lithium-ion batteries because it offers high theoretical capacity and low working potentials vs. Li⁺/Li. However, immense volume changes and the low intrinsic conductivity of Si hampers its practical applications. In this study, nano/micro silicon particles are achieved by ball milling silicon mesh powder as a scalable process. Subsequent metal (Cu/Fe/Mn) doping into nano/micro silicon by low-temperature annealing, followed by high-temperature annealing with graphite, gives a metal-doped silicon/graphite composite. The obtained composites were studied as anodes for Li-ion batteries, and they delivered high reversible capacities of more than 1000 mAh g^-1 with improved Li⁺ diffusion properties. The full cells from these composite anodes vs. LiCoO₂ cathodes delivered suitable energy densities for Li⁺ storage applications. The enhanced electrochemical properties are accredited to the synergistic effect of metal doping and graphite addition to silicon and exhibit potential for suitable Li⁺ energy storage applications.