Rechargeable lithium-ion batteries play an important role in energy storage because of their high power density. A key challenge for lithium-ion batteries is how to achieve high-rate performance and capacity at the same time, which has a huge impact on portable electronics, EVs and renewable energy smart grids. Although supercapacitors enable rapid charge and discharge, they are too low in capacity and expensive compared to lithium-ion batteries. Therefore, to improve the lithium ion battery capacity and capacity ratio is one of the hot spots in lithium research. Pan Feng, Research Institute of New Materials, Peking University Shenzhen Graduate School of Materials Recently, the research team combined the lithium iron phosphate manganese battery material with 3D printing technology to achieve the ultra-high rate performance and capacity of the battery. 3D printing has been rapidly developed in recent years due to its rapid prototyping and low cost. It can print materials of different thickness and width by controlling the flow rate and pressure, and its uniformity is also very good. 3D printing technology has been widely used in the field of lithium-ion micro-cells. This article skillfully achieves the combination of lithium iron phosphate-manganese battery material and 3D printing technology and prepares a 3D-printing electrode capable of 100 C Up to 1000 mAh cycles with current densities of 108 mAhg-1, 10 C and 20 C were retained at capacity of 150 and 140 mAhg-1. The research group then analyzed the experimental data of 3D printed electrodes and conventional electrodes by using Pseudo 2D Hidden Markov Model, and for the first time explained the key factors to achieve the high-rate performance of Li-ion batteries. The results show that the bulk diffusion of lithium ions is not a decisive factor in the rate performance at a current density of 100 C. However, solute diffusion, effective porosity and electrode thickness play a key role in achieving high rate capacity. At the same time, the calculation shows that after the electrode thickness exceeds a certain range, the above factors have a great influence on the equivalent diffusion coefficient, which determines the entire kinetic process of the lithium-ion battery. 3D printed lithium battery cathode material, Source: Advanced Energy Materials Manganese iron phosphate lithium battery material rate performance, Source: Advanced Energy Materials