The Research On Preparation And Lithium-Ion Batteries Performance Of LiMPO₄?M=Mn,Fe? Nanomaterials

Energy issues are related to the future survival and development of mankind,fossil energy is non-renewable energy,and one day will be depleted,looking for alternative new energy is the only way of human development.Today,there are potential new energy sources of such as solar energy and wind energy,they exist cyclical and intermittent characteristics,their characteristics make energy storage become the key.Many researchers have made every effort to study lithium-ion battery technology.However,up to now,lithium-ion battery technology still has some shortcomings.For example,the energy density is low,the safety performance is weaker,the battery life is shorter,and the preparation cost is high.Among them,the cathode material is characterized by low capacity performance and poor rate performance.These characteristics of the cathode material are the key to the control of lithium-ion battery technology.Therefore,the preparation of high specific capacity,high rate performance of the cathode material is the development of lithium-ion battery is one of the important breakthrough point.Cathode material has a olivine structure of the phosphate material,they have a high specific capacity,good stability,cheap and easy to get merit.However,LiMPO₄?M=Mn,Fe,etc.?materials also have disadvantages.Their own poor electrical conductivity.This is what our researchers need to make improvements and improve.LiMnPO₄ and LiFePO₄ in LiMPO₄?M=Mn,Fe,etc.?were studied in this paper.It is expected that LiMnPO₄ and LiFePO₄ can be used as the cathode materials by reducing the size,encapsulating carbon and reducing the graphene oxide.Preparation of In-situ Carbon LiMnPO₄/C Nanomaterials by organic solvent synthesis.The obtained materials were carbonized at different calcination temperatures to obtain LiMnPO₄/C nanomaterials at different calcination temperatures.Lithium-ion half-cells were prepared from materials of different carbonization temperatures?450?,550?,600?,650??.Through the test CV,impedance,magnification,cycle performance and other different temperature comparison.The relative optimum carbonization temperature was selected to be 550?.In addition,the LiMnPO₄/C nanomaterials at 550?carbonization temperature were subjected to XRD,SEM,TEM and HRTEM.A single crystal ultrafine LiFePO₄ two-dimensional nanosheets were prepared by organic solvent synthesis and had high{010}surface exposure.The self-assembled LiFePO₄/C composite nanosheet structure was formed by in-situ encapsulation of carbon nanotubes by calcination.The structure was a superfine structure with multi-layer structure with orientation.XRD,SEM,TEM,HRTEM,mapping and other test pieces of its structural composition.And then its lithium-ion battery preparation,its CV,impedance,magnification,cycle performance and commercial LiFePO₄/C compared.By comparison,the homemade material has higher performance than the commercial material,and the cycling stability is better.This is a very promising approach.The preparation of the template was carried out by adding GO to the initial solution by the method of organic solvent synthesis.Then,the obtained material was calcined in an Ar atmosphere to obtain a LiFePO₄/rGO material.Then,the prepared materials were characterized by XRD,SEM and TEM to characterize the morphology,size and crystal phase of the materials.Finally,it was prepared by lithium ion half-cell,and its CV,impedance,magnification,cycle performance and commercial LiFePO₄/C were compared.Comparison shows that homemade material as a whole than the commercial material rate performance is higher,better cycle stability.