13. Nano Transition Metal Alloy Functionalized Lithium Manganese Oxide Cathodes-System for Enhanced Lithium-Ion Battery Power Densities

A new generation of battery technologies is necessary to address the challenges of the increasingly complex energy systems our society requires. A lithium-ion battery (LIB) is an advanced battery technology that uses lithium ions as a key component of its electrochemistry. Manganese oxide cathode material of rechargeable lithium-ion batteries offers a unique blend of lower cost and toxicity compared to the normally used cobalt, and has been demonstrated to be safer on overcharge. The common disadvantages affecting its performance are amendable through morphological and electrochemical properties changes. In this research work, alloy nanoparticles were synthesized and used as coating material with the objective to improve the microstructure and catalytic activities of pristine LiMn₂O₄. Co-precipitation and calcination methods were used to coat the LiMn₂O₄. The pristine LiMn₂O₄ and modified materials were examined using a combination of spectroscopic and microscopic techniques along with in detail galvanostatic charge–discharge tests. Microscopic results revealed that the novel composite cathode materials had high phase purity, well-crystallized particles and consistent morphological structures with narrow size distributions. The LiPtAu_xMn_2−xO₄ cathode effectively accommodated the structural transformations, which occur during Li⁺ ion insertion with exchange current density i ₀ (A cm⁻²) of 1.83 × 10⁻⁴ and 3.18 × 10⁻⁴ for LiMn₂O_4. The enhancement of the capacity retention and higher electrode coulombic efficiency of the LiPtAu_xMn_2−xO₄ were significant, especially at high C rate. At enlarged cycling potential ranges the LiM_xMn_2−xO₄ (x = 0.02) sample delivered relevant discharge capacity of 90 mAh g⁻¹ compared to LiMn₂O₄ (45 mAh g⁻¹).