Atomic Layer Deposition of Metal-Fluorides on High-Voltage LiMn1.5Ni0.5O4 Cathode Powder

אודיטוריום ע " ש דיוויד וואנג , קומה 3, בנין דליה מידן
Ms. Ortal Tiurin

Ms. Ortal Tiurin, M.Sc. Candidate

Department of Materials Science and Engineering,
Technion – Israel Institute of Technology Haifa 3200003, Israel

Lithium Ion Batteries are the prime energy storage in multiple platforms including handheld devices (mobile phone, laptops, power tools) and electric vehicles (EV). Nonetheless, key challenges need to be addressed to pave the road for a reliable and long-lasting EV: The next generation battery will need to have higher energy density and should withstand higher operating temperatures. Higher energy density can be achieved by using high-voltage electrode materials, such as LiMn1.5Ni0.5O4 (LMNO). Aside from being inexpensive and more environmentally friendly than LiCoO2 (the industry standard), LMNO also has higher operating voltage (4.8V vs ~3.7V). Despite the many advantages of LMNO, its wide adaptation is halted due to one major disadvantage: Manganese dissolution into the electrolyte during battery operation. Therefore, the incorporation of a thin protective layer on the cathode, which would mitigate Mn dissolution, should improve the cells stability and durability. In this study, we attempted coating the LMNO with LiF to achieve enhanced protective characteristics. Despite its relatively low Li+ conduction, LiF is stable throughout the entire operating voltage of the battery and does not introduce additional contaminations. Electrochemical evaluation of the coated cathode material’s performance showed slightly lower capacity values, yet enhanced stability during prolonged cycling. Further fine-tuning of the ALD procedure may optimize both the protective characteristics and Li-ion conduction and promote enhanced capabilities for this high-voltage cathode material.

Supervisor: Prof. Yair Ein-Eli