Method for manufacturing structure
A method of preparing a structure, more particularly, a method of preparing a structure capable of ensuring a space for carrying an electrode active material by a simple method which includes an electrospinning process using a double nozzle electrospinning device and a heat treatment process.
1. A method for preparing a structure, comprising the following steps of:
(S 1 ) injecting a metal precursor solution and a carbon-based polymer solution into a double nozzle electrospinning device and electrospinning them to form a tube precursor having a core-shell structure,
wherein the metal precursor is at least one selected from the group consisting of alkoxide containing metal, acetyl acetate containing metal, nitrate containing metal, oxalate containing metal, halide containing metal and cyanide containing metal, and the metal is at least one selected from the group consisting of Au, Mg, Ag, Si and Ca;
(S 2 ) a first heat treatment step of heat-treating the tube precursor to carbonize the core of the tube precursor; and
(S 3 ) a second heat treatment step of heat-treating the tube precursor treated by the first heat treatment to form a tube structure.
2. The method for preparing the structure according to claim 1 , wherein the metal precursor solution and the carbon-based polymer solution are injected into an inner nozzle and an outer nozzle of the double nozzle electrospinning device, respectively, for electrospinning.
3. The method for preparing the structure according to claim 1 , wherein the metal precursor solution comprises 0.1 to 5 wt. % of a metal precursor; 1 to 20 wt. % of a polymer; and 75 to 95 wt. % of a solvent.
4. The method for preparing the structure according to claim 3 , wherein the polymer is at least one selected from the group consisting of polymethylmethacrylate (PMMA), polyvinyl pyrrolidone (PVP), polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), polystyrene (PS) and polyvinylidene fluoride (PVDF).
5. The method for preparing the structure according to claim 3 , wherein the solvent is at least one selected from the group consisting of NMP (methyl pyrrolidone), DMF (dimethylformamide), DMAc (dimethylacetamide), DMSO (dimethyl sulfoxide) and THF (tetrahydrofuran).
6. The method for preparing the structure according to claim 1 , wherein the carbon-based polymer is at least one selected from the group consisting of polyacrylonitrile (PAN), polyaniline (PANT), polypyrrole (PPY), polyimide (PI), polybenzimidazole (PBI), polypyrrolidone (Ppy), polyamide (PA), polyamide-imide (PAI), polyaramide, melamine, melamine formaldehyde and fluorine mica.
7. The method for preparing the structure according to claim 1 , wherein a temperature during the first heat treatment is 200 to 700° C.
8. The method for preparing the structure according to claim 1 , wherein a temperature during the second heat treatment is higher than 700° C. and not more than 1000° C.
9. The method for preparing the structure according to claim 1 , further comprising, after step (S 3 ), a step (S 4 ) of forming lithium metal in an interior of the tube structure.
10. The method for preparing the structure according to claim 9 , wherein the lithium metal is formed in the interior of the tube structure by electrolytic plating, electroless plating or vapor deposition.