A Simple Hot-Pressing Strategy for Thick Lithium Iron Phosphate Electrodes with Outstanding Electrochemical Properties

The growing demand for electric vehicles and renewable energy storage has intensified the need for Li-ion batteries with higher energy density. One effective strategy is the use of high mass loading electrodes, which increase the ratio between active and inactive materials. However, conventional tape casting techniques face challenges in producing thick electrodes as mechanical consistency deteriorates beyond a certain thickness. Alternative methods have been explored but often require changes in additives or compromise electrochemical performance. In this work, we present a simple and scalable modification of the traditional electrode fabrication process. By drying the NMP solvent before pressing and applying low-temperature hot pressing (190 °C), we obtain thick (150-650 μm), homogeneous, and mechanically robust electrodes that retain the use of standard additives such as carbon black and polyvinylidene fluoride (PVDF). A full cell composed of LFP/LP30/LTO delivered outstanding results: high areal capacities (17 and 13.5 mAh cm^-2 at C/25 and C/4), and exceptional cycling stability with no capacity loss over 300 cycles at C/12, despite a high loading of 120 mg cm^-2 (650 μm). This approach requires minimal changes to current industrial processes, offering a promising route for next-generation Li-ion batteries with improved energy density and performance.