Controllable Prepartion Of Micro-nano Structural MCo₂O₄?M=Ni,Cu,Mn? Materials And Their Application For Lithium Storage

With the merits of high theoretical capacity,rich redox chemistry and abundant resources,mixed transition metal oxides are one of the most promising anode materials in lithium-ion batteries.However,poor rate and cycling performance hinder their practical application due to large volume change during lithiation/delithiation.In this paper,three kinds of Co-based mixed transition mental oxides are prepared by solvothermal method and a subsequent annealing treatment approach and the lithium storage performances of them were studied as anode materials for lithium ion battery.The main research contents are as follows:1.The monodispersed porous NiCo₂O₄ microcubes were fabricated by urea-assisted solvothermal method and followed by an annealing treatment.Benefiting from the rich mesopores and primary nanoparticles with smaller size within microcubes,porous NiCo₂O₄ microcubes manifest excellent high specific capacity,outstanding rate capability,and good cycling performance,when investigated as anode materials for lithium-ion batteries.The porous NiCo₂O₄microcubes exhibit high initial discharge and charge capacities 1412 mAh g^-1 and1053 mAh g^-11 at a current density of 100 mA g^-1.At a current density of 400 mA g^-1,the discharge capacity of porous NiCo₂O₄ microcubes remains at 1067 mAh g^-1 after300 cycles with 98%of coulombic efficiency.2.The unique microsized assemblies constructed from porous CuCo₂O₄nanosheets?denoted as CuCo₂O₄ NSAs?were successfully perpared via a CTAB-assisted method.The as-synthesized CuCo₂O₄ nanosheet assemblies with desired structural and compositional features manifest excellent lithium storage performance in terms of superior rate capability(656 mAh g^-1 at 5 A g^-1)and long-term cycling life(600 cycles,1104 mAh g^-1 at 2 A g^-1).3.The uniform porous yolk-shelled MnCo₂O₄ microrugby balls?denoted as YSM-MCO?were synthesized by STAB-assisted solvothermal method and a subsequent annealing treatment approach.Owing to the desired porous structure,small primary building nanoparticles and composition,the as-ynthesized yolk-shelled MnCo₂O₄ microrugby balls exhibits enhanced lithium storage as advanced electrode materials in term of a high reversible capacity(1169 mAh g^-1 at 100 mA g^-1),excellent cycling stability(94%capacity retention over 200 cycles at 0.5 A g^-1)and outstanding rate performance(414 mAh g^-11 at 5 A g^-1).