Scalable thick Ni-rich layered oxide cathode design for high energy/power balanced lithium-ion battery

We have applied a scalable multilayer coating method to design three porous cathodes (90 μm thickness, areal loading ca. 25 mg cm−2, areal capacity ca. 5.3 mAh cm−2) based on LiNi0.9Co0.05Mn0.05O2 active materials in the form of small single-crystal (SSC) particles, large polycrystalline (LPC) secondary particles, and small polycrystalline (SPC) secondary particles. The V-type electrode facilitates Li+ transport, has a high characteristic thickness (46–57 μm), long cycle life with an active material utilization of 49.67% and a capacity retention of 88.24% after 100 cycles. The A-type electrode exhibits restricted Li+ transport, lower characteristic thickness (23–30 μm), fast cyclic capacity decay with an active material utilization of 26.31% and a capacity retention of 68.76% after 100 cycles. The small particles on the upper layer of the A-type electrode exhibit high-rate characteristics, exceeding 82.5% of the discharge capacity of a single-layer electrode with a uniform mixture of LPC and SSC at a 4C discharge rate. The combination of SSC and LPC particles facilitates high specific energy and cycling stability with optimum stability when stored at 60 °C under 100% state of charge (SOC). The design strategy that is proposed offers a commercial route to boosting battery energy density from 220 Wh kg−1 to above 300 Wh kg−1.