This study focuses on harnessing the advantages of prelithiation technology and prelithiation materials, also known as lithium supplements or prelithiation additives, by incorporating them into the positive electrode of lithium iron phosphate (LFP) batteries. Two battery prototypes were developed: A 51-Ah square aluminum-shell full battery with LFP and a 7-Ah soft-pack full battery. The cycle life of these batteries was tested and studied. Based on experience, the characteristics and impact on the battery life of main materials such as positive and negative electrodes (such as LFP, graphite, electrolyte ratio, current collector, and separator), auxiliary materials (positive and negative electrode adhesives, conductive agents, etc.), and prelithiation materials were analyzed. The lithium replenishment mechanism and lithium replenishment capacity of several prelithiation materials that have already been industrialized were analyzed through chemical reaction equations. Experimental results show that the cycle life of a 7 Ah battery with prelithiated materials reaches 9000 cycles, while a 7 Ah battery without prelithiated materials achieved 5300 cycles. The 7 Ah battery with prelithiated materials exhibits substantially better cycle performance compared to that without prelithiated materials, with a cycle life increase of over 50%. In terms of energy efficiency, the 7 Ah battery with prelithiated materials at 25 ℃ demonstrates an energy efficiency of 96.74% at 0.2 C, 94.80% at 0.5 C, and 92.67% at 1 C, surpassing the energy conversion efficiency of a 7 Ah battery without prelithiation materials. This research promotes the application of prelithiation technology and materials in long-cycle new energy storage LFP batteries. It provides an experimental basis and guidance for the design and development of long-life LFP batteries, thereby contributing to the advancement of energy storage systems.

Keywords： lithium iron phosphate (LFP) battery ; graphite ; electrolyte ; carbon coated aluminum foil ; prelithiation additive ; lithium supplement material