All-Cobalt-Free Layered/Olivine Mixed Cathode Material for High-Electrode Density and Enhanced Cycle-Life Performance
摘要
In this study, a high-energy-density electrode was fabricated by combining cobalt-free layered oxide (NM) with olivine LiFePO4 (LFP) nanoparticles. The resulting mixed all-cobalt-free cathode electrode effectively minimized electrode porosity by filling the interstitial spaces between the micron-sized layered-oxide particles with nanoscale LFP particles, significantly improving electrode density, and exhibiting excellent electrode conductivity. Furthermore, the composite electrode composed of NM and LFP achieved a volumetric capacity exceeding 600 mAh/cm− 3, comparable to that of typical layered oxide cathode materials, while also demonstrating enhanced cycle-life performance relative to electrodes composed solely of layered oxide or LFP. The enhanced electrochemical performance is attributed to the efficient lithium-ion and electron conduction facilitated by the intimate contact between NM and LFP particles, the suppression of NM particle degradation due to the relatively stable LFP particles on the NM surface, and the reduced particle fracture during roll-pressing. These improvements have been confirmed through electrochemical analyses and electrode observations.
Graphical Abstract