Versatile Ternary Manganese-Nickel-Cobalt Compounds in Multi-Shell Spherical Structures as Electrode Materials for High-Capacity Lithium-Ion Batteries

Electrochemical performance of rechargeable lithium ion batteries significantly relies on electrochemical properties of both cathode and anode materials. Nanostructured electrode materials have been demonstrated to improve cycling stability and rate capability for lithium ion batteries. Here, ternary manganese-nickel-cobalt carbonate (Mn_0.54Ni_0.13Co_0.13(CO₃)_0.8, marked as MNCCO₃) was first synthesized by hydrothermal method, which shows multi-shell spherical structure from numerous agglomerated nanoparticles. MNCCO₃ as anode material can deliver very high initial charge capacity of 997.8 mAh/g at a current density of 50 mA/g, and 821.2 mAh/g at 250 mA/g, respectively. Furthermore, the versatile ternary transition metal carbonate enables to produce two different derivates: manganese-nickel-cobalt oxide (0.54Mn₃O₄-0.13Co₃O₄-0.13NiO, marked as MNCO) in multi-shell caged structure after sintering and lithium-excess layered cathode material (Li[Li_0.2Mn_0.54Ni_0.13Co_0.13]O₂, marked as LMNCO) in yolk-shell structure after lithiation. The yielding MNCO as anode material shows outstanding cycling stability, which can retain charge capacity of 270.6 mAh/g after 100 electrochemical cycles at 250 mA/g. Simultaneously, LMNCO as cathode material delivers high initial discharge capacities of 250.7, 173.0 and 80.9 mAh/g at 25, 250 and 1250 mA/g, and can retain 156.3 mAh/g at 250 mA/g after 100 cycles, with remarkable corresponding capacity retention of 90.3%. The potential full battery from multifunctional ternary manganese-nickel-cobalt compounds, in which MNCCO₃ or MNCO as anode material and LMNCO as cathode material, can be fabricated for next generation high-capacity lithium ion batteries.