The particle size distribution(PSD)of active materials is one of the important performance parameters of the lithium ion battery electrode. Based on a multi-particle model with different particle size distributions,the electrochemical performance of the lithium ion battery was simulated and analyzed during its discharge process. The effects of different particles on the whole discharge process were illustrated,and the interactions between particles were discussed. Results indicate that the performance of Li-ion battery was greatly influenced by the PSD. In the early stage of the discharge, the intercalation reaction of lithium ion occurs mainly on the particles with small size,which are then saturated in the late stage. The particle surface reaction is transferred from small particles to large particles because they have more internal vacancies. Therefore,in the battery manufacturing process, the size of the electrode active material particles should be as uniform as possible,which can reduce the polarization caused by the nonuniform particles.%活性材料颗粒尺寸分布是锂离子电池电极的重要参数之一,对电池的电化学性能具有重要影响.基于多颗粒模型,本文对锂离子电池的电化学性能进行模拟和预测,分析了粒径分布对放电过程的影响,阐明了不同尺寸颗粒在整个放电过程中的作用以及不同尺寸颗粒间的相互作用.研究表明:在放电前期,锂离子的嵌入反应主要发生在小尺寸颗粒上;在放电后期,小尺寸颗粒嵌入的锂离子已接近饱和,电化学反应将在不同尺寸颗粒表面间转移,锂离子的嵌入反应主要发生在大尺寸颗粒上.因此,在电池制造中,均匀的电极活性材料粒度分布将有助于避免放电后期电极颗粒不均匀所引起的极化现象.
展开▼
