3. Positive electrodes

The search for the ideal positive electrode material for a lithium-ion battery has driven extensive fundamental and applied research in both academia and industry. An ideal positive electrode material has to meet several criteria. Firstly, it should contain an element that undergoes redox reactions during lithium insertion/extraction. These reactions should occur at a high potential (3 V higher than ${\text{Li}}^{+}\text{/Li}$ ). Its structure should have vacant spaces into which lithium ions can migrate and insert, providing a high lithium ion insertion capacity. The material should undergo minimal structural changes during insertion to maintain stable interactions with its environment and ensure reversibility during cycling. Secondly, since...