Research On The Controllable Preparation Of Three-dimensional Porous Cu₂S@Cu Based On Copper Current Collector And Its Energy Storage

Since its introduction in the 1990s,lithium-ion batteries have become one of the new energy sources with excellent development prospects due to their higher energy density,high voltage,good cycle performance,and good cycle life.They are considered to be ideal choices for high-power batteries.Cu₂S electrode materials have been widely concerned and studied due to their high theoretical specific capacity,low price,simple preparation process,and environmental friendliness.However,the traditionally coated Cu₂S electrode material has low performance due to its poor electrical conductivity,large expansion and contraction during the charge and discharge process,which has limited the development of commercialization to a certain extent.How to improve the electrical conductivity of materials and stabilize the structural properties of materials has been the direction of continuous research and exploration.In this subject,a non-solvent-induced phase separation method?NIPS method?was used in combination with the sintering process,and a 1?m particle size copper powder was used as the raw material to successfully prepare a three-dimensional double-connected porous copper with uniform pore size distribution,high porosity,and certain mechanical properties.A flat film current collector was used as the current collector,and Cu₂S was grown in situ as a negative electrode material for lithium ions by a chemical reaction method.The anode material has the characteristics of stable specific capacity,high energy density,and simple and fast preparation process.The findings are as follows:?1?Using a copper powder with a particle size of 1?m as a raw material,a casting film solution with a copper content of 54.5wt%was prepared.The thickness of the scraping film was set to 250?m.The oxidation parameters and reduction temperatures were sintered at 600?to obtain the best parameters.Connected porous copper flat membrane.?2?Using the flat film under the optimal preparation process parameters as a current collector.Cu₂S was grown in situ by chemical methods as an electrode material for lithium ions.Using sodium mercaptoate as a catalyst,the reaction activation energy of copper and sulfur was reduced by the combined action of mercaptoethanol and sodium hydroxide,and Cu₂S material grown in situ on a porous copper flat film could be prepared under normal temperature conditions.The optimal preparation parameters were mercaptoethanol:sodium hydroxide:sulfur:copper 3:3:1:20.?3?According to the morphology and electrochemical characterization of the Cu₂S electrode material,it can be known that the Cu₂S negative electrode material obtained by this preparation method is affected by conditions such as the ratio of S and Cu and the porosity of the current collector.A too high ratio of S to Cu will cause the material to be easily broken and powdered during preparation and electrochemical testing.Too low current collector porosity will hinder the growth of the material on the current collector.Therefore,in the process of preparing the Cu₂S electrode material,the optimal performance is obtained by considering the appropriate preparation parameters.?4?From the electrochemical test results,it can be understood that the area specific capacity of the electrode material with a sulfur-copper ratio of 1:20 can be maintained at 1000?Ah cm^-2 at a current density of 200?A cm^-2.The specific capacity can still reach 1006.8?Ah cm^-2 after 100 cycles.When the current density is increased to 1.0m A cm^-2,the specific capacity can still be maintained at about 300?Ah cm^-2.After 100cycles of the cell the specific capacity is still available 312.3?Ah cm^-2.The preparation process provides a new idea for the preparation of copper sulfide anode materials and the application of porous current collectors in lithium ion batteries.