METHOD FOR MANUFACTURING ELECTRODE STRUCTURE FOR POSITIVE ELECTRODE, ELECTRODE STRUCTURE MANUFACTURED THEREBY, AND SECONDARY BATTERY COMPRISING SAME
Provided is a method for manufacturing an electrode structure. The method for manufacturing an electrode structure may comprise the steps of: preparing a first precursor having a chalcogen element, a second precursor having phosphorus, and a third precursor having a transition metal; preparing a suspension by mixing the first precursor, the second precursor, and the third precursor in a first solvent; adding a reducing agent to the suspension and causing a reaction therebetween to produce an intermediate product; and adding the intermediate product and a surfactant to a second solvent and heat-treating under pressure, to thereby manufacture an electrode structure comprising the chalcogen element, the phosphorus, and the transition metal.
1 . A method for manufacturing an electrode structure, the method comprising:
providing a first precursor having a chalcogen element, a second precursor having phosphorus, and a third precursor having a transition metal;
preparing a suspension by mixing the first precursor, the second precursor, and the third precursor in a first solvent;
adding a reducing agent to the suspension and causing a reaction therebetween to produce an intermediate product; and
adding the intermediate product and a surfactant to a second solvent and heat-treating under pressure, to manufacture an electrode structure including the chalcogen element, the phosphorus, and the transition metal.
2 . The method of claim 1 , wherein the preparing of the intermediate product comprises adding the reducing agent to the suspension, and then stirring the suspension at normal temperature.
3 . The method of claim 1 , wherein the first precursor comprises at least one of dithiooxamide, thiourea, ammonium sulfide, sodium sulfide, thioacetamide, or sodium thiophosphate;
the second precursor comprises at least one of phosphorus acid, ifosfamide, triphenylphosphine, tetradecylphosphonic acid, or sodium thiophosphate; and
the third precursor comprises at least one of a transition metal chloride, a transition metal sulfide, or a transition metal nitride.
4 . The method of claim 1 , wherein the surfactant comprises at least one of Triton X-165, Triton X-100, H 2 SO 4 , HCl, hexamethylenetetramine, hexadecyltrimethylammonium bromide, ammonium sulfate, polyoxyethylene, dodecanol, tridecane, or stearic acid.
5 . The method of claim 1 , wherein the first solvent and the second solvent comprise at least one of alcohol, DMF, oleic acid, oleylamine, 1-octadecene, trioctylphosphine, ethylenediamine, pyrrolidone, tributylamine, amine-based solvent, or deionized water.
6 . The method of claim 1 , wherein the transition metal comprises at least one of Cu, Mn, Fe, Co, Ni, Zn, Mg, or Ca.
7 . The method of claim 1 , wherein the electrode structure is in a form of a plurality of fibrillated fibers including a plurality of stems and a plurality of branches branched off from the plurality of stems.
8 . The method of claim 7 , wherein the intermediate product in a form of the plurality of stems is formed in a process of adding the reducing agent to the suspension and causing a reaction therebetween,
and the plurality of branches are formed in a process of adding the intermediate product and the surfactant to the second solvent and heat-treating under pressure.
9 . The method of claim 1 , wherein a bifunctional activity, which is a difference value between overpotentials of ORR and OER of the electrode structure, is controlled by at least one of a type of the first precursor, a type of the second precursor, a type of the transition metal of the third precursor, a type of the surfactant, a type of the first solvent, or a type of the second solvent.
10 . A method for manufacturing an electrode structure, the method comprising:
providing a first precursor having sulfur, a second precursor having phosphorus, and a third precursor having a transition metal in a first solvent including alcohol, adding a reducing agent, stirring, and causing a reaction therebetween at normal temperature to prepare an intermediate product; and
adding the intermediate product and a surfactant to a second solvent including alcohol and heat-treating under pressure to manufacture an electrode structure for a positive electrode of a secondary battery including a compound of the transition metal, sulfur, and phosphorus.
11 . The method of claim 10 , wherein the electrode structure is a positive electrode of a metal-air secondary battery or a lithium ion secondary battery.
12 . The method of claim 10 , wherein the first precursor comprises at least one of dithiooxamide, thioacetamide, or ammonium sulfide;
the second precursor comprises at least one of phosphorus acid or ifosfamide;
the transition metal of the third precursor comprises at least one of Cu, Fe, or Mn; and
the surfactant comprises at least one of Triton X-165, Triton X-100, or HCl.
13 . An electrode structure for a positive electrode of a secondary battery, wherein the electrode structure comprises a membrane in which a plurality of fibrillated fibers formed of a compound of a transition metal, phosphorus and sulfur form a network.
14 . The method of claim 13 , wherein the plurality of fibers formed of a compound of a transition metal, phosphorus and sulfur comprises a plurality of stems, and a plurality of branches branched off from the plurality of stems; and
the membrane of the electrode structure has a sponge structure and is flexible.
15 . An electrode structure for a positive electrode of a lithium ion secondary battery for intercalating and deintercalating lithium ions during a charge/discharge process,
wherein the electrode structure comprises a compound of a transition metal, sulfur and phosphorus.
16 . The electrode structure of claim 15 , wherein the transition metal of the electrode structure comprises at least one of copper, magnesium, manganese, cobalt, iron, nickel, titanium, zinc, aluminum, or tin.
17 . The electrode structure of claim 15 , the electrode structure comprises a membrane in which a plurality of fibers which are fibrillated by a plurality of stems and a plurality of branches branched off from the plurality of stems form a network.
18 . The electrode structure of claim 15 , the transition metal of the electrode structure comprises copper, and
the electrode structure is represented by <Formula 1> below.
CuP x S y <Formula 1>
(wherein x+y=1, 0.3≤x≤0.7, 0.3≤y≤0.7)
19 . The electrode structure of claim 15 , the electrode structure has a sponge structure and is flexible.
20 . A lithium ion secondary battery comprising:
a positive electrode including the electrode structure of claim 15 ;
a negative electrode on the positive electrode; and
an electrolyte between the positive electrode and the negative electrode.