Use of TiO۲ Nanoparticles as Air Cathode Modifier in Rechargeable Lithium-Air Batteries to Improvement of Performance

Today, Li-O۲ rechargeable batteries are the most attractive energy storage devices used for electric vehicles because to their high energy density. A Li-O۲ battery is composed of an air cathode, electrolyte containing Li, and Li metal as an anode. However, there are many limitations for this batteries, such as short cycling life, capacity and lifetime more due to the deposition of the insulated Li۲O۲ (as discharge product) on the cathode pore leads to fading capacity and a high overpotential. It is found that the developing catalyst such as transition metals, transition metals oxide and noble metals in these batteries cathode for O۲ electro-reduction process is the one effective key to improving battery performance and to overcome many cathode limitations. For this reason, TiO۲ is an attractive electrocatalyst with excellent electrochemical activities due to its۲high stability, unique physicochemical properties. This work aims to observe the electrochemical performance of TiO۲ as an air cathode modifier. However, TiO۲ nanoparticles were synthesized via the facile sol-gel method and investigated as air cathode modifier in lithium-air batteries. The phase structure, surface morphology, and elemental composition of the synthesized TiO۲ nanoparticles were characterized as well. Additionally, the TiO۲ as nanocatalyst was deposited on the cathode carbon sheets, and their electrochemical performances of lithium-oxygen were evaluated via an ECC-Air test cell using cyclic voltammetry, electrochemical impedance measurements, and galvanostatic charge-discharge tests. Consequently, the air cathode containing TiO۲ showed a full discharge capacity of ۲۰۰۰ mAh/g and a specific capacity of ۵۰۰ mAh/g for ۱۲۰ stable cycles. Interestingly, the discharge potential increases from ۲.۳۵ V to ۲.۹۰ V and so the overpotential amount of the battery was decreased.