Lithium iron orthosilicate (LFS) cathode can be prepared via the polyol-assisted ball milling method with the incorporation of carbon derived from eggshell membrane (ESM) for improving inherent poor electronic conduction. The powder X-ray diffraction (XRD) pattern confirmed the diffraction peaks without any presence of further impure phase. Overall, 9 wt.% of carbon was loaded on the LFS, which was identified using thermogravimetric analysis. The nature of carbon was described using parameters such as monolayer, and average surface area was 53.5 and 24 m² g⁻¹ with the aid of Langmuir and Brunauer–Emmett–Teller (BET) surface area respectively. The binding energy was observed at 285.66 eV for C–N owing to the nitrogen content in eggshell membrane, which provides more charge carriers for conduction. Transmission electron microscopy (TEM) images clearly show the carbon coating on the LFS, the porous nature of carbon, and the atom arrangements. From the cyclic voltammetry (CV) curve, the ratio of the anodic to the cathodic peak current was calculated as 1.03, which reveals that the materials possess good reversibility. Due to the reversibility of the redox mechanism, the material exhibits discharge specific capacity of 194 mAh g⁻¹ for the first cycle, with capacity retention and an average coulombic efficiency of 94.7% and 98.5% up to 50 cycles.

Superior sodium-ion-conducting polymer poly(vinyledene fluoride)–silicon dioxide (PVdF-SiO₂) composite separator membrane was prepared via simple phase inversion method, which is a suitable alternative conventional polypropylene membrane. Basically, PVdF is the promising for use as high porous polymer electrolyte membrane due to its high dielectric constant (ε = 8.4). In this work, we prepared a composite membrane using PVdF-SiO₂ via phase inversion method. This work was systematically studied towards the morphology, porosity, and electrochemical properties of as prepared membrane. The electrolyte uptake capability of separator membrane tested with 1 M NaPF₆ electrolyte solution and temperature-dependent ionic conduction test were performed at various temperatures. This membrane exhibits higher ionic conductivity of 4.7 × 10⁻² S cm⁻¹ at room temperature. The physical properties were analyzed by X-ray diffraction, FT-IR, and FE-SEM micrographs analyses. The electrochemical performances with impedance analysis carried for prepared membrane with the as-prepared sodium P2-type cathode material. The material showed an initial discharge capacity of 178 mAh g⁻¹ at 0.1 C between 2 and 4 V with 98% columbic efficiency and 81% capacity retention after 50 cycles upon using the as-prepared PVdF-SiO₂ composite separator membrane.

A prismatic type layered Na_2/3Ni_1/3Mn_2/3O₂ cathode material for a sodium ion battery is prepared via two different methods viz., the solid state and sol–gel method with dissimilar surface morphology and a single phase crystal structure. It shows tremendous electrochemical chattels when studied as a cathode for a sodium-ion battery of an initial specific discharge capacity of 244 mAh g⁻¹ with decent columbic efficiency of 98% up to 250 cycles, between the voltage range from 1.8 to 4.5 V (Na⁺/Na) at 0.1 C under room temperature. It is much higher than its theoretical value of 173 mAh g⁻¹ and also than in the earlier reports (228 m Ah g⁻¹). The full cell containing this material exhibits 800 mAh g⁻¹ at 0.1 C and withstands until 1000 cycles with the discharge capacity of 164 mAh g⁻¹. The surpassing capacity was expected by the anionic (oxygen) redox process, which elucidates the higher capacity based on the charge compensation phenomenon.