High-Energy Density Core–Shell Structured Li[Ni_0.95Co_0.025Mn_0.025]O₂ Cathode for Lithium-Ion Batteries

High-Energy Density Core–Shell Structured Li[Ni_0.95Co_0.025Mn_0.025]O₂ Cathode for Lithium-Ion Batterie

Extending the Battery Life Using an Al-Doped Li[Ni_0.76Co_0.09Mn_0.15]O₂ Cathode with Concentration Gradients for Lithium Ion Batteries

The cycling stability of a Ni-enriched compositionally graded Li­[Ni_0.76Co_0.09Mn_0.15]­O₂ cathode doped with Al (1 and 2 mol %) was explicitly demonstrated by cycling the cathodes in a full cell against a graphite anode up to 1000 cycles. Without Al doping, the pristine gradient cathode retained 88% of the initial discharge capacity, whereas the 2 mol % Al-doped gradient cathode retained 95% of its original capacity. Meanwhile, Li­[Ni_0.82Co_0.14Al_0.04]­O₂ (NCA), representing a typical cathode for commercialized electric vehicles, retained only 80% of the initial capacity. It was shown that Al doping together with the unique morphology of the compositionally graded cathode was able to suppress the microcracking and helped to preserve the mechanical integrity of the cathode particles, whereas the benchmark NCA cathode sustained continuous capacity loss during cycling and was completely pulverized. The remarkable long-term cyclability of the Al-doped gradient cathodes was attributed to the enhanced structural and the surface stabilization, which also improved the thermal stability

Microstructure- and Interface-Modified Ni-Rich Cathode for High-Energy-Density All-Solid-State Lithium Batteries

Electric vehicles powered by Li-ion batteries pose a potential safety risk because the flammable liquid electrolytes can, under certain conditions, cause explosions. All-solid-state batteries (ASSBs) are safe alternative battery technologies. However, realizing high-energy-density ASSBs by employing Ni-rich layered cathodes is difficult because of the detrimental volume contraction near charge end. This study shows that the simultaneous B doping and coating of a Ni-rich Li[Ni0.9Co0.05Mn0.05]O2 cathode, which modifies the cathode microstructure and cathode–solid electrolyte interface, respectively, afford an ASSB that cycles stably for 300 cycles with minimal capacity fading. An ASSB featuring the B-doped, B-coated Li[Ni0.9Co0.05Mn0.05]O2 cathode demonstrates a discharge capacity of 214 mAh g–1, which represents one of the highest discharge capacities achieved by an ASSB; moreover, the ASSB retains 91% of its initial capacity after 300 cycles and easily outperforms previously reported ASSBs in terms of energy density without compromising cycling stability