Descriptor-Based Graded Electrode Microstructures Design Strategies of Lithium-Ion Batteries for Enhanced Rate Performance

Microstructure engineering of electrodes is one the efficient routes to improve rate performance lithium-ion batteries (LIBs). Currently, there a lack descriptors rationally guide regional electrode design. Here, we propose two descriptors, time differential average state lithium (SoL) and span SoL in individual particles, identify constraints across depth. 3D microstructure-based electrochemical simulations are performed on homogeneous electrode, predictability model verified with experimental measurement LiNi1/3Mn1/3Co1/3O2 electrode. At level, divide into four regions, namely, solid-state transport (SST)-controlled region, mixed SST liquid-state (LST)-controlled regions (SST-dominant LST-dominant, respectively), an LST-controlled region. Based these insights, dual-gradient designed smaller particles SST-controlled region graded porosity increasing from current collector separator. Results show that optimized has significantly more excellent LST capability compared thus improving utilization near collector. As result, capacity increases by 39% at 5C without sacrificing gravimetric energy density.