Fabrication and Performance Analysis of LMO/g-CN Cathode for Lithium-Ion Battery

<p>Lithium-ion batteries (LIBs) are widely used for renewable energy storage due to their high efficiency and reliability. Spinel LiMn₂O₄ (LMO) is a promising cathode material because of its high power capability, low cost, and abundance, but its practical application is limited by poor cycle life caused by manganese dissolution and structural instability. This study investigates graphitic carbon nitride (g-C₃N₄), particularly its exfoliated form, as a stabilizing additive to improve LMO performance. LMO was synthesized via the sol–gel method, while g-C₃N₄ was prepared by thermal condensation followed by exfoliation, and the LMO/g-C₃N₄ nanocomposite was obtained through mixing, stirring, and drying. Electrodes were fabricated using polyvinyl alcohol (PVA) as a binder and graphite as a conductive agent. X-ray diffraction confirmed the retention of LMO’s cubic spinel structure, while exfoliated g-C₃N₄ exhibited a broadened (002) peak at 13.1° (2θ), indicating nanosheet morphology. Scanning electron microscopy revealed smooth, polyhedral LMO particles (~550 nm) and layered g-C₃N₄ flakes, with the composite showing uniform dispersion of LMO on g-C₃N₄ surfaces, facilitating improved lithium-ion transport. Impedance analysis showed lower resistance for pure LMO, while g-C₃N₄ modified interfacial properties and may enhance long-term stability. Electrochemical testing demonstrated a significant improvement in performance, with the LMO/g-C₃N₄ electrode achieving a specific capacity of 15.5 µAh g⁻¹ compared to 4 µAh g⁻¹ for pure LMO, along with better stability and reduced self-discharge. These findings indicate that LMO/g-C₃N₄ nanocomposites offer a promising, low-cost, and environmentally friendly strategy for advanced energy storage applications in hybrid electronics and automotive systems.</p>