Al-Doped Co-Free Layered-Spinel Mn/Ni Oxides as High-Capacity Cathode Materials for Advanced Li-Ion Batteries

Li- and Mn-rich layered-spinel integrated cathodes exhibit a high specific capacity, >= 200 mAh g-1, in a wide potential range; however, the low initial capacity of Li[Ni1/3Mn2/3]O2 is a drawback for Li[Ni0.33Mn0.63Al0.03]O2 and Li[Ni0.33Mn0.60Al0.06]O2 cathode materials which were synthesized by self-combustion reaction, having less monoclinic and more active spinel phases, could show a much higher initial capacity compared to the undoped reference material. These cathode materials exhibit an initial specific capacity of 188 mAh g-1 vs similar to 110 mAh g-1 when cycled at 20 mA g-1 between 2.3 and 4.9 V vs Li. Their capacity gradually increases to 210 mAh g-1 during initial cycling in standard electrolyte solutions and stabilizes thereafter. The average discharge voltage decreases from around 3.6 to 3.2 V after 200 cycles. the lower impedance due to lower surface film and charge-transfer resistance of the cathodes comprising the Al-doped materials compared to cathodes comprising the reference, undoped material. The high specific capacity and excellent cycling stability of Li[Ni0.33Mn0.60Al0.06]O2 render it a promising cathode material for high-energy Li-ion batteries.

Automated summary

Li- and Mn-rich layered-spinel integrated cathodes with Al doping exhibit high specific capacity and excellent cycling stability, making them promising cathode materials for high-energy Li-ion batteries.