2D MXene/LiFePO4 Hybrid as Cathode for Lithium-Ion Batteries

Rechargeable lithium-ion batteries (LIBs) are nowadays one of the most popular energy storage devices. LIBs are unparalleled in terms of high energy and power density combination. Among the different available cathode materials, lithium iron phosphate LiFePO4 (LFP) has been considered the material of choice for high power applications owing to its thermal and structural stability in the fully charge state, its little hygroscopicity, and its exceptional high-rate charge/discharge performance. However, the low intrinsic electronic conductivity and the low diffusion coefficient of lithium ions in the olivine-type crystal structure of LFP has hindered its widespread application in industry. Recently a family of novel 2D metal carbide/nitride materials with unique surface chemistry, adjustable composition, and remarkable physical chemical properties have been used in energy conversion and storage (ECS) applications. These materials are known as MXenes. In this project, we propose to boost LFP cathode performance by integrating LFP nanoparticles with MXene nanosheets using simple wet-chemistry methods. In the hybrid, MXene with ultrahigh conductivity and large surface area will improve the power and energy density of LFP cathode via rapid ion/electron transport and additional Li-ion adsorption sites, respectively. Besides, 2D MXene can also prevent LFP aggregation and therefore improve the electrode tap density.