Research On Transition Metal Doped Lithium Battery Cathode Materials

LiNi_1/3Co_1/3Mn_1/3O₂ has been widely investigated by many researchers owing to its high reversible capacity,stable structure,and enhanced thermal stability and relatively low cost.However,as the thorough study of transition metal oxide electrode materials,researcher found that stable performance gradually became poor after a lot times of charge and discharge.In addition,the rapid capacity fading and inferior rate capabilities of LiNi_1/3Co_1/3Mn_1/3O₂ are still the main problems preventing its sustainability and use in high power applications.In the context,we first discuss about the two synthesized electrode materials which are transition metals doping and electrochemical performance.LiNi_1/3Cu_xCo_1/3-xMn_1/3O₂ and LiFe_xNi?1/3-x?Co_1/3Mn_1/3O₂?0.000 ? x ? 0.267?microspheres have been synthesized by substituting stoichiometric copper for cobalt and iron for nickel,respectively.The specific capacity of the copper-doped material is relatively low due to the aggregation of particles and the generation of impurities.Appropriate amount of iron doping can increase the specific capacity.LiNi_1/3Zn_xCo_1/3-xMn_1/3O₂?0.000 ? x ? 0.133?microspheres are synthesized using MnO₂ microspheres both as a self-template and Mn source.These hollow microspheres, 4 ?m in diameter,are composed of approximately 300 nm basic nanoparticles.The XRD patterns of LiNi_1/3Zn_xCo_1/3-xMn_1/3O₂ were analyzed by the RIETAN-FP program,and the obtained samples have a layered ?-Na FeO₂ structure.Electrochemical performances were carried out between 2.5 V and 4.5 V.The behavior of the lattice parameters is consistent with cycling performance and rate performance change with increase of Zn-doped.Compared with the others,the sample of x = 0.133 exhibits a relatively superior electrochemical performance.The specific capacity of x = 0.133 was increased by 10.7% than no-doped.In addition,loose or porous structure of LiNi_1/3Zn_xCo_1/3-xMn_1/3O₂?x = 0.133?hollow microspheres materials is advantageous to the transport of lithium ion within electrode materials,and can be a buffering reservoir to store electrolyte and further provide a shorter pathway for Li-ion diffusion and charge transfer.