Design And Performance Investigation On Efficient Carbon-Based Catalysts For Li-O₂ And Li-CO₂ Batteries

In a large number of secondary energy,lithium air battery has a very high theoretical than the energy,far greater than the current commercial lithium-ion battery,at the same time with environmental protection,low price characteristics,Have high hopes.At present,lithium oxygen battery and lithium carbon dioxide attract people’s attention as the two best developed branches.However,lithium-ion battery is still a serious polarization phenomenon,the electrolyte evaporation and decomposition,the cycle performance is not ideal,power performance is not ideal and easy to corrosion of metal lithium cathode and other issues.The improvement in battery performance relies on the selection and optimization of positive electrode catalysts.Highly efficient catalyst materials can significantly improve the battery reaction process lagging behind the reaction kinetics,reduce the overcurrent,improve the charge and discharge efficiency.In addition,the microstructure of the catalyst will also have a significant impact on the performance of lithium air cells,and the catalyst with high specific surface area can effectively improve the capacity and circulation performance of lithium-air batteries.(1)Firstly,The Present Paper carried out the fabrication of two-dimensional Co-N-C and performance testing of Li-O2 cell(02 + 2Li(?)Li2O2).We prepare Co@PNCS precursor by mechanically mixing carbon source,nitrogen source and cobalt source.Hierarchical porous Co@NC structure were prepared using a facile one-pot pyrolysis route for lithium-O2 batteries.Preliminary experimental results showed that the Co@HNCS has good catalytic performance in lithium-O2 batteries.Compared with other literature results,the primary discharge capacity of the Co@HNCS electrode was significantly improved and the cycle life of the electrode exceeded 120 cycles with a fixed capacity of 600 mAh g-1.At the same time,DFT test illustrated that the adsorption energy of Co(111)was higher than that of Graphitic-N,Pyridinic-N and other binding methods.At last,the optimal structure and electrochemical properties of the two-dimensional Co-N-C material were explored.(2)In addition,The Present Paper introduces some research for Li-CO2 batteries.As an ideal energy source to alleviate the greenhouse efifect and future Mars immigrants,LCBs has the difference mechanism copared with Li-O2 batteries(3CO2 + 4Li 2Li2CO3 + C).We tried to find a kind of material with high catalytic activity for resolving lithium carbonate effectively.After referring to relevant literatures,it was found that Ir had a high catalytic activity.Ir particles were uniformly modified on three-dimensional CNT skeleton structure by hydrothermal reaction.Then we explored the optimal catalytic activity of Ir-CNT according to the content of different doping.It was found that 1:3 was the optimal content for Ir-CNT.The charging voltage platform of Ir-CNT was about 4.0V lower than the general catalyst.It had a good cycling performance of up to 100 cycles.