KR102444415B1 - Reduced graphene oxide-silicon metal particle composite formed by light irradiation, a method for producing the composite, and a electrode for secondary battery including the composite - Google Patents
Reduced graphene oxide-silicon metal particle composite formed by light irradiation, a method for producing the composite, and a electrode for secondary battery including the composite Download PDFInfo
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Abstract
본 발명은, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체, 복합체 제조방법 및 복합체를 포함하는 이차전지용 전극에 있어서, 코어-쉘 구조의 그래핀-실리콘 금속입자 분말을 준비하는 단계와; 상기 그래핀-실리콘 금속입자 분말에 광조사하여 재결정된 산화그래핀환원물-실리콘 금속입자 복합체를 얻는 단계를 포함하는 것을 기술적 요지로 한다. 이에 의해 양이온-파이 상호작용을 통해 형성되는 저결함/고순도 산화그래핀을 수용성 폴리머를 이용하여 실리콘 금속입자와 혼합된 분산용액을 제조한 후 건조하여 코어-쉘 구조의 복합체를 형성하고, 이를 고에너지를 갖는 광을 조사하여 산화그래핀을 순간적으로 환원 및 재결정함으로써 전기전도도 성능이 복구되는 복합체 및 이차전지용 전극을 얻을 수 있다.The present invention relates to a graphene oxide reduced product-silicon metal particle composite formed through light irradiation, a method for manufacturing the composite, and an electrode for a secondary battery comprising the composite, preparing a core-shell structure graphene-silicon metal particle powder Wow; It is a technical gist to include the step of obtaining a recrystallized graphene oxide reduced product-silicon metal particle composite by irradiating the graphene-silicon metal particle powder with light. Thereby, a dispersion solution of low-defect/high-purity graphene oxide formed through cation-pi interaction is mixed with silicon metal particles using a water-soluble polymer, and then dried to form a core-shell structure complex, which is By irradiating light with energy to instantaneously reduce and recrystallize graphene oxide, it is possible to obtain composites and electrodes for secondary batteries in which electrical conductivity performance is restored.
Description
본 발명은 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체, 복합체 제조방법 및 복합체를 포함하는 이차전지용 전극에 관한 것으로, 더욱 상세하게는 양이온-파이 상호작용을 통해 형성되는 저결함/고순도 산화그래핀을 수용성 폴리머를 이용하여 실리콘 금속입자와 혼합된 분산용액을 제조한 후 건조하여 코어-쉘 구조의 복합체를 형성하고, 이를 고에너지를 갖는 광을 조사하여 산화그래핀을 순간적으로 환원 및 재결정함으로써 전기전도도 성능이 복구되는 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체, 복합체 제조방법 및 복합체를 포함하는 이차전지용 전극에 관한 것이다.The present invention relates to a graphene oxide reduced product-silicon metal particle composite formed through light irradiation, a method for manufacturing the composite, and an electrode for a secondary battery comprising the composite, and more particularly, to a low-defect / formed through cation-pi interaction After preparing a dispersion solution of high-purity graphene oxide mixed with silicon metal particles using a water-soluble polymer, drying it to form a core-shell structure complex, and irradiating it with high-energy light to instantly reduce graphene oxide And graphene oxide reduced product formed through light irradiation to recover electrical conductivity by recrystallization - to a secondary battery electrode comprising a silicon metal particle composite, a composite manufacturing method and the composite.
최근 소형화, 경량화된 각종 전자기기와 더불어 초대형 전력저장시스템에 대한 수요가 급증함에 따라 새로운 에너지원에 대해 전 세계적인 관심이 높아지고 있다. 그중에서도 친환경적이며 높은 에너지 밀도를 지니고 급속 충/방전이 가능한 이차전지 분야에 대한 연구 개발이 집중되고 있다. 특히 리튬이차천지의 음극활물질로 사용되는 탄소계, 금속계, 산화물계 물질들은 종류가 다양할 뿐만 아니라 고출력, 고밀도 에너지 전력향상에 핵심적인 역할을 하고 있어 많은 연구 및 상용화가 이루어지고 있다. 그 중 음극활물질로 언급되는 탄소계 물질 중 흑연(graphite)은 매우 안정적이고 부피팽창을 수반하지 않는 매우 우수한 재료이지만, 이론적인 용량의 한계로 인해 고용량을 요구하는 모바일 기기에 부응하는 음극활물질로는 미흡한 실정이다. 따라서 음극활물질로 새로운 고용량 소재를 요구하고 있는데 그 중 실리콘(Si)이 높은 이론용량을 가지고 있다. 실리콘은 리튬(Li)과 합금화(alloying), 합금부식화(dealloying)을 통하여 리튬 이온의 충방전이 가능한 금속 원소로서, 기존 음극활물질 재료인 흑연에 비하여 무게당, 부피당 용량에 월등한 특성을 보이기 때문에 차세대 고용량 리튬이차전지 재료로서 활발히 연구되고 있다.Recently, as the demand for ultra-large power storage systems along with miniaturized and light-weighted various electronic devices has increased, global interest in new energy sources is increasing. Among them, research and development are focused on the secondary battery field, which is environmentally friendly, has high energy density, and can be rapidly charged/discharged. In particular, carbon-based, metal-based, and oxide-based materials used as anode active materials for lithium secondary systems are not only diverse, but also play a key role in improving high-output, high-density energy power. Among carbon-based materials referred to as anode active materials, graphite is a very stable and excellent material that does not involve volume expansion. It is insufficient. Therefore, a new high-capacity material is required as an anode active material. Among them, silicon (Si) has a high theoretical capacity. Silicon is a metal element capable of charging and discharging lithium ions through alloying and dealloying with lithium (Li). Therefore, it is being actively studied as a next-generation high-capacity lithium secondary battery material.
하지만 실리콘이 높은 이론용량 특성을 보임에도 불구하고 상용화가 쉽지 않은 이유는, 리튬 이온을 흡수 및 저장시 결정구조의 변화에 의해 300% 이상의 큰 부피팽창이 발생하게 된다. 또한 계속된 부피변화로 인해 실리콘의 구조가 와해되는 현상이 야기된다. 이를 통해 초기 효율 및 사이클 특성이 저하되기 때문에 리튬이차전지의 가역성을 향상시키며, 고용량을 유지하는 기술이 필수적이게 된다.However, the reason why silicon is not easy to commercialize despite its high theoretical capacity is that when lithium ions are absorbed and stored, a large volume expansion of 300% or more occurs due to a change in the crystal structure. In addition, a phenomenon in which the structure of silicon is broken due to the continuous volume change is caused. As a result, the initial efficiency and cycle characteristics are lowered, so a technology for improving the reversibility of the lithium secondary battery and maintaining a high capacity is essential.
이를 위해 종래기술 '대한민국특허청 공개특허 제10-2015-0116238호 그래핀-금속나노입자복합체, 상기 복합체를 포함하는 탄소나노섬유복합체 및 상기 탄소나노입자복합체를 포함하는 이차전지' 및 '대한민국특허청 등록특허 제10-1634723호 실리콘 슬러지로부터 실리콘-카본-그래핀 복합체의 제조방법'과 같이 금속입자의 표면을 개질하고 이를 산화그래핀과 반응시켜 그래핀이 랩핑된 금속입자를 만드는 기술이 알려져 있다. 하지만 이와 같은 경우 금속입자를 표면개질하는 단계와, 산화그래핀이 금속입자를 랩핑한 후 환원하는 단계를 거쳐야 하기 때문에 제조 단계가 복잡하다는 단점이 있다. 또한 산화그래핀을 환원하는 과정에서 열처리에 의해 금속입자가 산화되는 등 상태가 변형되는 문제점이 생길 수도 있다.To this end, prior art 'Korea Patent Office Laid-Open Patent No. 10-2015-0116238 Graphene-Metal Nanoparticle Composite, a carbon nanofiber composite including the composite and a secondary battery including the carbon nanoparticle composite' and 'Registered with the Korea Intellectual Property Office As in Patent No. 10-1634723, 'Method for manufacturing a silicon-carbon-graphene composite from silicon sludge', a technique for making metal particles wrapped with graphene by modifying the surface of metal particles and reacting them with graphene oxide is known. However, in this case, there is a disadvantage in that the manufacturing step is complicated because the step of surface-modifying the metal particles and the step of reducing the graphene oxide after wrapping the metal particles are required. In addition, in the process of reducing graphene oxide, there may be a problem in that the state is deformed, such as metal particles are oxidized by heat treatment.
따라서 본 발명의 목적은, 양이온-파이 상호작용을 통해 형성되는 저결함/고순도 산화그래핀을 수용성 폴리머를 이용하여 실리콘 금속입자와 혼합된 분산용액을 제조한 후 건조하여 코어-쉘 구조의 복합체를 형성하고, 이를 고에너지를 갖는 광을 조사하여 산화그래핀을 순간적으로 환원 및 재결정함으로써 전기전도도 성능이 복구되는 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체, 복합체 제조방법 및 복합체를 포함하는 이차전지용 전극을 제공하는 것이다.Therefore, an object of the present invention is to prepare a dispersion solution in which low-defect/high-purity graphene oxide formed through cation-pi interaction is mixed with silicon metal particles using a water-soluble polymer, and then dried to obtain a core-shell structure composite. Formed and irradiated with light having high energy to instantaneously reduce and recrystallize graphene oxide, thereby recovering the electrical conductivity of the graphene oxide reduced product-silicon metal particle composite, composite manufacturing method and composite It is to provide an electrode for a secondary battery comprising.
상기한 목적은, 양이온-파이 상호작용을 통해 형성된 그래핀 분산용액, 수용성 폴리머 및 실리콘 금속입자를 혼합한 분산용액을 분무건조하여, 상기 실리콘 금속입자가 코어이고, 상기 그래핀이 상기 실리콘 금속입자를 둘러싸는 쉘로 형성되는, 코어-쉘 구조의 그래핀-실리콘 금속입자 분말을 제조하는 단계; 및 상기 그래핀-실리콘 금속입자 분말에 광조사하여 산화그래핀환원물-실리콘 금속입자 복합체를 얻는 단계;를 포함하되, 상기 산화그래핀환원물-실리콘 금속입자 복합체는, 상기 광조사를 통하여 상기 그래핀이 상기 산화그래핀환원물로 환원됨과 동시에 재결정되어 전기전도도가 우수한 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체 제조방법에 의해서 달성된다.The above object is to spray-dry a graphene dispersion solution formed through cation-pi interaction, a dispersion solution in which a water-soluble polymer and silicon metal particles are mixed, so that the silicon metal particle is the core, and the graphene is the silicon metal particle Formed as a shell surrounding the, core-shell structure graphene-preparing a silicon metal particle powder; and obtaining a graphene oxide-reduced-silicon metal particle complex by irradiating the graphene-silicon metal particle powder with light; including, wherein the graphene oxide-reduced-silicon metal particle composite is, through the light irradiation Graphene is reduced and recrystallized at the same time as the reduced graphene oxide, which is characterized in that it has excellent electrical conductivity.
여기서, 상기 그래핀은 산화그래핀이며, 상기 코어-쉘 구조의 그래핀-실리콘 금속입자 분말을 준비하는 단계는, 그래파이트를 산화하여 산화그래파이트를 형성하는 단계와; 상기 산화그래파이트를 분산 및 박리하여 산화그래핀을 형성하는 단계와; 양이온-파이 상호작용을 통해 상기 산화그래핀을 포함하는 산화그래핀 분산용액을 제조하는 단계와; 상기 산화그래핀 분산용액을 수용성 폴리머 및 실리콘 금속입자와 혼합하여 산화그래핀-실리콘 금속입자 분산용액을 제조하는 단계와; 상기 산화그래핀-실리콘 금속입자 분산액을 건조하여 코어-쉘 구조의 복합체 분말을 제조하는 단계를 포함하며, 상기 광조사를 통해 상기 산화그래핀이 환원됨과 동시에 재결정되는 것이 바람직하다.Here, the graphene is graphene oxide, and the preparation of the graphene-silicon metal particle powder of the core-shell structure includes: oxidizing the graphite to form graphite oxide; dispersing and exfoliating the graphite oxide to form graphene oxide; Preparing a graphene oxide dispersion solution containing the graphene oxide through a cation-pi interaction; mixing the graphene oxide dispersion solution with a water-soluble polymer and silicon metal particles to prepare a graphene oxide-silicon metal particle dispersion solution; It is preferable that the graphene oxide-silicon metal particle dispersion is dried to prepare a composite powder having a core-shell structure, and the graphene oxide is reduced and recrystallized at the same time through the light irradiation.
또는, 상기 그래핀은 산화그래핀환원물이며, 상기 코어-쉘 구조의 그래핀-실리콘 금속입자 분말을 준비하는 단계는, 그래파이트를 산화하여 산화그래파이트를 형성하는 단계와; 상기 산화그래파이트를 분산 및 박리하여 산화그래핀을 형성하는 단계와; 양이온-파이 상호작용을 통해 상기 산화그래핀을 포함하는 산화그래핀 분산용액을 제조하는 단계와; 상기 산화그래핀 분산용액을 환원시켜 산화그래핀환원물 분산용액을 제조하는 단계와; 상기 산화그래핀환원물 분산용액을 수용성 폴리머 및 실리콘 금속입자와 혼합하여 산화그래핀환원물-실리콘 금속입자 분산용액을 제조하는 단계와; 상기 산화그래핀환원물-실리콘 금속입자 분산액을 건조하여 코어-쉘 구조의 복합체 분말을 제조하는 단계를 포함하는 것이 바람직하다.Alternatively, the graphene is a reduced graphene oxide, and the preparing of the graphene-silicon metal particle powder of the core-shell structure includes: oxidizing graphite to form graphite oxide; dispersing and exfoliating the graphite oxide to form graphene oxide; Preparing a graphene oxide dispersion solution containing the graphene oxide through a cation-pi interaction; reducing the graphene oxide dispersion to prepare a reduced graphene oxide dispersion; mixing the graphene oxide reduced product dispersion solution with a water-soluble polymer and silicon metal particles to prepare a graphene oxide reduced product-silicon metal particle dispersion solution; Preferably, the method includes drying the reduced graphene oxide-silicon metal particle dispersion to prepare a composite powder having a core-shell structure.
또한, 상기 산화그래파이트를 형성하는 단계는, 그래파이트 플레이크를 산처리를 통해 합성하며, 상기 산처리는 상기 그래파이트 플레이크에 농질산(fuming nitric acid) 또는 황산(sulfuric acid)에 소듐클로레이트(NaClO4) 또는 포타슘퍼망가네이트(KMnO4)를 첨가하여 교반을 통해 이루어지는 것이 바람직하다.In addition, in the step of forming the graphite oxide, graphite flakes are synthesized through acid treatment, and the acid treatment is sodium chlorate (NaClO 4 ) or sulfuric acid in fuming nitric acid or sulfuric acid in the graphite flakes. Potassium permanganate (KMnO 4 ) is preferably added through stirring.
상기 산화그래핀 분산용액을 형성하는 단계는, 상기 산화그래핀을 알칼리 용매에 분산 및 박리하여 산화그래핀 분산용액을 형성하는 단계와; 상기 산화그래핀 분산용액 내에 탄소 원자들이 2차원 상에서 sp2결합에 의해 연결된 배열의 중심에 양이온을 위치시킴에 의해, 양이온과 sp2영역의 파이구조와의 양이온-파이 상호작용을 통해 양이온반응 산화그래핀 분산용액을 형성하는 단계를 포함하는 것을 특징으로 하는 광조사를 통해 형성되는 것이 바람직하다.The forming of the graphene oxide dispersion solution includes: dispersing and exfoliating the graphene oxide in an alkaline solvent to form a graphene oxide dispersion solution; By locating cations at the center of an arrangement in which carbon atoms are connected by sp 2 bonds in two dimensions in the graphene oxide dispersion solution, cation-reaction oxidation with cations and pi structures of sp 2 regions through cation-pi interaction It is preferably formed through light irradiation, characterized in that it comprises the step of forming a graphene dispersion solution.
상기 산화그래핀 분산용액을 형성하는 단계는, 상기 산화그래핀환원물과 상기 실리콘 금속입자가 물에서 분산성이 우수하도록 상기 수용성 폴리머를 추가하여 혼합하는 것이 바람직하다.In the step of forming the graphene oxide dispersion solution, it is preferable to add and mix the water-soluble polymer so that the graphene oxide reduced product and the silicon metal particles have excellent dispersibility in water.
상기 광조사는, 파장이 300 내지 1,000nm, 펄스폭(pulse width)은 0.1 내지 100ms, 펄스갭(pulse gap)은 0.1 내지 100ms, 펄스수(pulse number)는 1 내지 10,000번, 에너지밀도(energy density)는 1 내지 300J/㎠인 것이 바람직하다.The light irradiation has a wavelength of 300 to 1,000 nm, a pulse width of 0.1 to 100 ms, a pulse gap of 0.1 to 100 ms, a pulse number of 1 to 10,000 times, and energy density (energy). density) is preferably 1 to 300 J/cm 2 .
상기한 목적은, 양이온-파이 상호작용을 통해 형성된 그래핀 분산용액, 수용성 폴리머 및 실리콘 금속입자를 혼합한 분산용액을 분무건조하여, 상기 실리콘 금속입자가 코어이고, 상기 그래핀이 상기 실리콘 금속입자를 둘러싸는 쉘로 형성되는, 코어-쉘 구조의 그래핀-실리콘 금속입자 분말에 광조사하여 형성되는 산화그래핀환원물-실리콘 금속입자 복합체로서, 상기 산화그래핀환원물-실리콘 금속입자 복합체는, 상기 광조사를 통하여 상기 그래핀이 상기 산화그래핀환원물로 환원됨과 동시에 재결정되어 전기전도도가 우수한 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체에 의해서도 달성된다.The above object is to spray-dry a graphene dispersion solution formed through cation-pi interaction, a dispersion solution in which a water-soluble polymer and silicon metal particles are mixed, so that the silicon metal particle is the core, and the graphene is the silicon metal particle As a graphene oxide reduced product-silicon metal particle composite formed by light irradiation to a core-shell structure graphene-silicon metal particle powder, the graphene oxide reduced product-silicon metal particle composite comprises: Through the light irradiation, the graphene is reduced to the graphene oxide reduced product and recrystallized at the same time to have excellent electrical conductivity, and it is also achieved by the graphene oxide reduced product formed through light irradiation-silicon metal particle composite.
상기한 목적은 또한, 집전체; 및 상기 집전체의 일면에 형성되고 산화그래핀환원물-실리콘 금속입자 복합체를 갖는 활물질;로 이루어지며, 상기 산화그래핀환원물-실리콘 금속입자 복합체는, 양이온-파이 상호작용을 통해 형성된 그래핀 분산용액, 수용성 폴리머 및 실리콘 금속입자를 혼합한 분산용액을 분무건조하여, 상기 실리콘 금속입자가 코어이고, 상기 그래핀이 상기 실리콘 금속입자를 둘러싸는 쉘로 형성되는, 코어-쉘 구조의 그래핀-실리콘 금속입자 분말에 광조사하여 형성되는 것이되, 상기 광조사를 통하여 상기 그래핀이 상기 산화그래핀환원물로 환원됨과 동시에 재결정되어 전기전도도가 우수한 것을 특징으로 하는, 이차전지용 전극에 의해서도 달성된다.The above object is also a current collector; and an active material formed on one surface of the current collector and having a graphene oxide reduced product-silicon metal particle complex, wherein the graphene oxide reduced product-silicon metal particle complex is formed through cation-pi interaction By spray-drying a dispersion solution in which a dispersion solution, a water-soluble polymer and a silicon metal particle are mixed, the silicon metal particle is a core, and the graphene is formed as a shell surrounding the silicon metal particle, core-shell structure graphene- It is formed by irradiating the silicon metal particle powder with light, and through the light irradiation, the graphene is reduced to the graphene oxide reduced product and recrystallized at the same time, which is characterized by excellent electrical conductivity. It is also achieved by an electrode for a secondary battery .
본 발명에 따르면, 양이온-파이 상호작용을 통해 형성되는 저결함/고순도 산화그래핀을 수용성 폴리머를 이용하여 실리콘 금속입자와 혼합된 분산용액을 제조한 후 건조하여 코어-쉘 구조의 복합체를 형성하고, 이를 고에너지를 갖는 광을 조사하여 산화그래핀을 순간적으로 환원 및 재결정함으로써 전기전도도 성능이 복구되는 복합체 및 이차전지용 전극을 얻을 수 있다.According to the present invention, a dispersion solution of low-defect/high-purity graphene oxide formed through cation-pi interaction is mixed with silicon metal particles using a water-soluble polymer, and then dried to form a core-shell structure complex, , it is possible to obtain a composite and a secondary battery electrode in which electrical conductivity is restored by instantaneously reducing and recrystallizing graphene oxide by irradiating it with light having high energy.
도 1은 본 발명의 제1실시예에 따른 산화그래핀환원물-실리콘 금속입자 복합체 제조방법의 순서도이고,
도 2는 제2실시예에 따른 산화그래핀환원물-실리콘 금속입자 복합체 제조방법의 순서도이고,
도 3은 실시예 1에 의해 제조된 산화그래핀환원물-실리콘 금속입자 복합체의 주사전자현미경 사진이고,
도 4는 비교예 1에 의해 제조된 산화그래핀환원물-실리콘 금속입자 복합체의 주사전자현미경 사진이고,
도 5는 실시예 1 및 비교예 1에에 따른 라만스펙트럼이고,
도 6은 실시예 및 비교예에 따른 임피던스 그래프이고,
도 7은 실시예 및 비교예에 따른 전기화학특성 그래프이다.1 is a flow chart of a method for manufacturing a reduced graphene oxide-silicon metal particle composite according to a first embodiment of the present invention;
2 is a flow chart of a method for manufacturing a reduced graphene oxide-silicon metal particle composite according to a second embodiment;
3 is a scanning electron microscope photograph of the graphene oxide reduced product-silicon metal particle composite prepared in Example 1;
4 is a scanning electron microscope photograph of the graphene oxide reduced product-silicon metal particle composite prepared by Comparative Example 1;
5 is a Raman spectrum according to Example 1 and Comparative Example 1,
6 is an impedance graph according to Examples and Comparative Examples,
7 is a graph showing electrochemical properties according to Examples and Comparative Examples.
이하에서는 본 발명의 실시예에 따른 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체, 복합체 제조방법 및 복합체를 포함하는 이차전지용 전극을 도면을 통해 상세히 설명한다.Hereinafter, graphene oxide reduced product-silicon metal particle composite formed through light irradiation according to an embodiment of the present invention, a method for manufacturing the composite, and an electrode for a secondary battery including the composite will be described in detail with reference to the drawings.
본 발명에 따른 산화그래핀환원물-실리콘 금속입자 복합체는, 코어-쉘 구조의 그래핀-실리콘 금속입자 분말에 광조사하여 재결정된 것에 해당한다. 이와 같은 복합체를 포함하는 이차전지용 전극은, 집전체와; 상기 집전체의 일면에 형성되며 산화그래핀환원물-실리콘 금속입자 복합체를 갖는 활물질로 이루어지며, 산화그래핀환원물-실리콘 금속입자 복합체는, 코어-쉘 구조의 그래핀-실리콘 금속입자 분말에 광조사하여 재결정된 것이 바람직하다.The graphene oxide reduced product-silicon metal particle composite according to the present invention corresponds to a core-shell structure graphene-silicon metal particle powder recrystallized by irradiation with light. An electrode for a secondary battery comprising such a composite includes a current collector; It is formed on one surface of the current collector and is made of an active material having a graphene oxide reduced product-silicon metal particle composite, and the graphene oxide reduced product-silicon metal particle composite is a core-shell structure graphene-silicon metal particle powder. It is preferable to recrystallize by irradiation with light.
이와 같은 산화그래핀환원물-실리콘 금속입자 복합체 제조방법의 제1실시예는 도 1에 도시된 바와 같이 먼저, 그래파이트를 산화하여 산화그래파이트를 형성한다(S1a).As shown in FIG. 1, in the first embodiment of the graphene oxide reduced product-silicon metal particle composite manufacturing method, first, graphite is oxidized to form graphite oxide (S1a).
분말상태의 그래파이트 플레이크(graphite flake)로부터 분말상태의 산화그래파이트 분말을 합성한다. 산화그래파이트 분말은 분말상태의 99.9995%의 고순도 그래파이트 플레이크를 산처리를 통해 합성한 후 수용액의 반복 세척과정과 원심분리기를 이용하여 불순물을 제거함으로써 얻어진다. 산처리는 고순도 그래파이트 플레이크에 농질산(fuming nitric acid) 또는 황산(sulfuric acid) 등과 같은 강산에 소듐클로레이트(NaClO4) 또는 포타슘퍼망가네이트(KMnO4)를 첨가하여 상온에서 48시간 교반을 통해 산화시킨다. 그리고 증류수를 사용하여 중화시킨 후 필터링(filtering) 및 워싱(washing)을 반복한다. 산화된 그래파이트 용액은 건조과정을 거친 후 그라인딩(grinding)을 이용하여 산화그래파이트 분말을 얻는다.The graphite oxide powder in the powder state is synthesized from the graphite flake in the powder state. Graphite oxide powder is obtained by synthesizing 99.9995% of high-purity graphite flakes in a powder state through acid treatment, followed by repeated washing of an aqueous solution and removing impurities using a centrifuge. Acid treatment is oxidized by adding sodium chlorate (NaClO 4 ) or potassium permanganate (KMnO 4 ) to a strong acid such as fuming nitric acid or sulfuric acid to high-purity graphite flakes and stirring at room temperature for 48 hours. . And after neutralization using distilled water, filtering (filtering) and washing (washing) are repeated. After the oxidized graphite solution is dried, a graphite oxide powder is obtained by grinding.
여기서 산처리는 일반적으로 사용하는 스타우덴마이어법(L. Staudenmaier, Ber. Dtsch. Chem. Gas., 31, 1481-1499, 1898), 험머스법(W. Hummers 외 1명, J. Am. Chem. Soc., 80, 1339, 1958), 브로디법(B. C. Brodie Ann. Chim.Phys., 59, 466-472, 1860), 호프만법(W. S Hofmann 외 1명, Z. Anorg. Allg. Chem. 234, 311-335, 1937), 투어법(J. M. Tour 외 8명, ACS Nano, 4, 4806-4814, 2010) 중에서 선택하여 사용할 수 있다.Here, the acid treatment is generally used by the Staudenmaier method (L. Staudenmaier, Ber. Dtsch. Chem. Gas., 31, 1481-1499, 1898), the Hummers method (W. Hummers et al., J. Am. Chem. Soc., 80, 1339, 1958), Brodie's method (B. C. Brodie Ann. Chim. Phys., 59, 466-472, 1860), Hoffman's method (W. S Hofmann et al., Z. Anorg. Allg. Chem) 234, 311-335, 1937) and the tour method (J. M. Tour et al. 8, ACS Nano, 4, 4806-4814, 2010).
산화그래파이트를 분산 및 박리하여 산화그래핀을 형성한다(S2a).Graphite oxide is dispersed and exfoliated to form graphene oxide (S2a).
S1 단계에서 제조된 산화그래파이트 분말을 용매에 분산하여 산화그래파이트 분산용액을 만들고, 분산용액 내에서 산화그래파이트를 박리하여 저결함/고순도 산화그래핀을 형성한다.The graphite oxide powder prepared in step S1 is dispersed in a solvent to make a graphite oxide dispersion solution, and the graphite oxide is peeled off in the dispersion solution to form low-defect/high-purity graphene oxide.
산화그래파이트 분말을 분산하기 위한 용매는 알칼리 용매가 바람직한데, 알칼리 용매는 수산화나트륨(NaOH) 수용액, 수산화칼륨(KOH) 수용액, 수산화암모늄(NH4H) 수용액, 수산화리튬(LiOH) 수용액, 수산화칼슘(Ca(OH)2) 수용액 및 이의 혼합물로 이루어진 군에서 선택되는 것을 사용하며, 용매의 pH는 8 이상부터 분산이 가능하며 가장 바람직한 pH는 10 이상이다.The solvent for dispersing the graphite oxide powder is preferably an alkaline solvent, and the alkaline solvent is an aqueous sodium hydroxide (NaOH) solution, a potassium hydroxide (KOH) aqueous solution, an ammonium hydroxide (NH 4 H) aqueous solution, a lithium hydroxide (LiOH) aqueous solution, and a calcium hydroxide ( Ca(OH) 2 ) A solution selected from the group consisting of aqueous solutions and mixtures thereof is used, and the pH of the solvent can be dispersed from 8 or more, and the most preferable pH is 10 or more.
산화그래파이트 분산용액에 초음파 분쇄(sonication), 호모게나이저(homogenizer), 고압균질기(high pressurehomogenizer) 중 하나 이상을 사용하여 산화그래파이트의 분산 및 박리가 이루어진다. 이때 분산 및 박리시 필요한 시간은 10분 내지 5시간으로, 10분 미만일 경우 분산 및 박리가 원활히 이루어지지 않으며, 5시간을 초과할 경우 결함 형성이 많아져 고품질 산화그래핀을 얻을 수 없다.Dispersion and exfoliation of graphite oxide is performed using one or more of ultrasonic pulverization, homogenizer, and high pressure homogenizer in the graphite oxide dispersion solution. At this time, the time required for dispersion and exfoliation is 10 minutes to 5 hours, and when it is less than 10 minutes, dispersion and exfoliation are not smoothly performed, and when it exceeds 5 hours, defect formation increases and high-quality graphene oxide cannot be obtained.
양이온-파이 상호작용을 통해 단일층 산화그래핀 분산용액을 제조한다(S3a).A single-layer graphene oxide dispersion solution is prepared through cation-pi interaction (S3a).
분산 및 박리된 산화그래핀을 양이온-파이 상호작용을 통하여 양이온반응 산화그래핀 분산용액을 형성한다. 이를 상세히 설명하면 산화그래핀을 알칼리 용매와 산화그래핀을 분산 및 박리하여 산화그래핀 분산용액을 형성하는 단계와, 산화그래핀 분산용액 내에 탄소 원자들이 2차원 상에서 sp2결합에 의해 연결된 배열의 중심에 양이온을 위치시킴에 의해, 양이온과 sp2영역의 파이구조와의 양이온-파이 상호작용을 통해 양이온반응 산화그래핀 분산용액을 형성하는 단계로 이루어진다.The dispersed and exfoliated graphene oxide forms a cation-reactive graphene oxide dispersion solution through cation-pi interaction. To describe this in detail, the steps of dispersing and exfoliating graphene oxide with an alkali solvent and graphene oxide to form a graphene oxide dispersion, and an arrangement in which carbon atoms in the graphene oxide dispersion are connected by sp 2 bonds in two dimensions By positioning the cation in the center, the cation and the cation-pi interaction of the sp 2 region of the pi structure consist of a step of forming a cation-reactive graphene oxide dispersion solution.
양이온반응 산화그래핀 분산용액은 초음파 분쇄 등과 같은 외부의 물리적 힘이 가해지지 않은 상태에서 산화그래핀 분산용액을 상온에서 1분 내지 10시간 정도의 반응시간을 유지함으로써 얻어질 수 있다.The cationic reaction graphene oxide dispersion solution can be obtained by maintaining the graphene oxide dispersion solution at room temperature for a reaction time of about 1 minute to 10 hours in a state where external physical force, such as ultrasonic grinding, is not applied.
여기서 산화그래핀 분산용액의 농도 범위가 1mg/L 내지 50g/L인 상태에서 상온에서 10분 정도의 반응 시간을 유지함으로써 얻어질 수 있다. 이때 산화그래핀 분산용액 농도의 범위가 1mg/L 미만일 경우 고농도 산화그래핀 형성이 어려우며, 산화그래핀 분산용액의 농도 범위가 50g/L을 초과할 경우 산화그래핀의 뭉침현상이 일어나는 단점이 있다.Here, it can be obtained by maintaining a reaction time of about 10 minutes at room temperature in a state where the concentration range of the graphene oxide dispersion is 1 mg/L to 50 g/L. At this time, when the concentration range of the graphene oxide dispersion solution is less than 1 mg/L, it is difficult to form high-concentration graphene oxide, and when the concentration range of the graphene oxide dispersion solution exceeds 50 g/L, there is a disadvantage that agglomeration of the graphene oxide occurs. .
이러한 반응은, 도 1에 도시된 바와 같이 산화그래핀 분산용액에 포함된 알칼리 용매를 통하여 나트륨(Na+), 칼륨(K+), 암모늄(NH4 +), 리튬(Li+)과 같은 일가 양이온과 육각형 sp2영역의 파이 구조와의 반응을 활성화시키는 것으로서, 알칼리용매의 약환원반응을 통한 산화그래핀의 산소작용기 제거 및 양이온과의 상호작용을 위한 반응시간의 유지를 통하여 형성되는 것이다. 도 1은 첨가된 용매가 수산화나트륨 수용액이며, 양이온은 나트륨이온이다.This reaction, as shown in Figure 1, sodium (Na + ), potassium (K + ), ammonium (NH 4 + ), lithium (Li + ) through the alkaline solvent contained in the graphene oxide dispersion solution, such as monovalent It activates the reaction between the cation and the pi structure of the hexagonal sp 2 region, and is formed by removing the oxygen functional group of graphene oxide through the weak reduction reaction of an alkali solvent and maintaining the reaction time for interaction with the cation. 1 shows that the added solvent is an aqueous sodium hydroxide solution, and the cation is sodium ion.
양이온반응 산화그래핀 분산용액을 제조는 양이온-파이 상호작용의 활성화를 위해서 회전증발법, 원심분리법, 교반법 등과 같은 용매휘발법을 이용할 수 있다. 이는 약환원을 통하여 양이온이 흡착할 수 있는 그래핀의 육각형 sp2영역을 보다 증가시키기 위하여 온도와 시간을 조절함으로써 국부적인 산화작용기를 제거한다. 그리고 용매휘발법을 이용하여 물을 증발시킴으로서 양이온-파이 상호작용을 활성화시키며 고농도 분산용액을 제조한다.To prepare a cation-reactive graphene oxide dispersion solution, a solvent volatilization method such as rotary evaporation, centrifugation, and stirring may be used to activate the cation-pi interaction. This removes the local oxidation functional group by controlling the temperature and time to further increase the hexagonal sp 2 region of graphene that can be adsorbed by cations through weak reduction. And by evaporating water using the solvent volatilization method, the cation-pi interaction is activated and a high concentration dispersion solution is prepared.
산화그래핀 분산용액을 수용성 폴리머 및 실리콘 금속입자와 혼합하여 산화그래핀-실리콘 금속입자 분산용액을 제조한다(S4a).The graphene oxide dispersion solution is mixed with a water-soluble polymer and silicon metal particles to prepare a graphene oxide-silicon metal particle dispersion solution (S4a).
표면에 개질이 이루어지지 않은 순수한 상태의 실리콘 금속입자를 준비하고 S3a 단계를 통해 제조된 산화그래핀 분산용액을 수용성 폴리머 및 실리콘 금속입자와 혼합하여 산화그래핀-실리콘 금속입자 분산용액을 제조한다. 산화그래핀 분산용액의 경우 물을 포함하고 있으나 산화그래핀 및 실리콘 금속입자는 물에 골고루 분산되지 않는다는 단점이 있다. 따라서 산화그래핀과 실리콘 금속입자가 물에서 분산성이 우수하도록 수용성 폴리머를 추가하여 혼합하고, 이를 통해 산화그래핀-실리콘 금속입자 분산용액을 제조한다.Prepare silicon metal particles in a pure state that are not modified on the surface, and mix the graphene oxide dispersion solution prepared through step S3a with a water-soluble polymer and silicon metal particles to prepare a graphene oxide-silicon metal particle dispersion solution. Although the graphene oxide dispersion solution contains water, there is a disadvantage that graphene oxide and silicon metal particles are not evenly dispersed in water. Therefore, a water-soluble polymer is added and mixed so that graphene oxide and silicon metal particles have excellent dispersibility in water, and through this, a graphene oxide-silicon metal particle dispersion solution is prepared.
여기서 수용성 폴리머는 폴리비닐알콜(Polyvinyl alcohol), 폴리에틸렌글리콜(Polyethylene glycol), 폴리에틸렌이민(Polyethyleneimine), 폴리아마이드아민(Polyamideamine), 폴리비닐포름아미드(Polyvinyl formamide), 폴리비닐아세테이트(Polyvinyl acetate), 폴리아크릴아마이드(Polyacrylamide), 폴리비닐피롤리돈(Polyvinylpyrrolidone), 폴리디알릴디메틸암모늄클로라이드, 폴리에틸렌옥사이드(Polyethyleneoxide), 폴리아크릴산(Polyacrylic acid), 폴리스티렌설폰산(Polystyrenesulfonic acid), 폴리규산(Polysilicic acid), 폴리인산(Polyphosphoric acid), 폴리에틸렌설폰산(Polyethylenesulfonic acid), 폴리-3-비닐록시프로펜-1-설폰산(Poly-3-vinyloxypropane-1-sulfonic acid), 폴리-4-비닐페놀(Poly-4-vinylphenol), 폴리-4-비닐페닐설폰산(Poly-4-vinylphenyl sulfuric acid), 폴리에틸렌포스포릭산(Polyethyleneohosphoric acid), 폴리말릭산(Polymaleic acid), 폴리-4-비닐벤조산(Poly-4-vinylbenzoic acid), 메틸셀룰로오스(Methyl cellulose), 하이드록시에틸셀룰로오스(Hydroxy ethyl cellulose), 카복시메틸셀룰로오스(Carboxy methyl cellulose), 소듐카복시메틸셀룰로오스(Sodium carboxy methyl cellulose), 하이드록시프로필셀룰로오스(Hydroxy propyl cellulose), 소듐카복시메틸셀룰로오스(Sodium carboxymethylcellulose), 폴리사카라이드(Polysaccharide), 전분(Starch) 및 이의 혼합으로 이루어진 군으로부터 선택되는 것이 바람직하나 이에 한정되지는 않는다.Here, the water-soluble polymer is polyvinyl alcohol, polyethylene glycol, polyethyleneimine, polyamideamine, polyvinyl formamide, polyvinyl acetate, polyvinyl acetate. acrylamide, polyvinylpyrrolidone, polydiallyldimethylammonium chloride, polyethyleneoxide, polyacrylic acid, polystyrenesulfonic acid, polysilicic acid, Polyphosphoric acid, Polyethylenesulfonic acid, Poly-3-vinyloxypropane-1-sulfonic acid, Poly-4-vinylphenol 4-vinylphenol), poly-4-vinylphenyl sulfuric acid, polyethyleneohosphoric acid, polymaleic acid, poly-4-vinylbenzoic acid (Poly-4) -vinylbenzoic acid), methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium carboxy methyl cellulose, hydroxypropyl cellulose ), sodium carboxymethylcellulose, polysaccharide, starch, and mixtures thereof, but preferably selected from the group consisting of does not lose
산화그래핀-실리콘 금속입자 분산용액을 건조하여 코어-쉘 구조의 분말을 제조한다(S5a).The graphene oxide-silicon metal particle dispersion solution is dried to prepare a powder having a core-shell structure (S5a).
S4a 단계를 통해 제조된 산화그래핀-실리콘 금속입자 분산용액을 건조하여 실리콘 금속입자는 코어(core)로 내부에 존재하고 산화그래핀은 실리콘 금속입자의 주위를 둘러싸는 형태의 외부 쉘(shell) 구조로 이루어진 코어-쉘 구조의 분말을 제조한다.By drying the graphene oxide-silicon metal particle dispersion solution prepared through step S4a, the silicon metal particles are present inside as a core, and the graphene oxide is an outer shell in the form of surrounding the silicon metal particles. A powder having a core-shell structure consisting of a structure is prepared.
이때 산화그래핀-실리콘 금속입자 분산용액을 건조하는 방법으로는 분무건조가 가장 바람직한데, 분무건조의 경우 한 번만 이루어져도 무방하나 실리콘 금속입자의 주위를 산화그래핀이 완벽하게 둘러싸기 위해서는 두, 세 번 이상으로 분무건조를 수행하는 것이 바람직하다. 이때 분무건조는 산화그래핀-실리콘 금속입자 분산용액을 여러 번 분무시키나, 필요에 따라서 산화그래핀-실리콘 금속입자 분산용액을 분무시킨 후 산화그래핀만 존재하는 분산용액을 분무건조하여 실리콘 표면을 둘러싸도록 구성할 수도 있다. 분무건조 중 수용성폴리머와 물은 증발되고 산화그래핀과 실리콘 금속입자 만이 남게되어 코어-쉘 구조의 분말을 형성하게 된다.At this time, as a method of drying the graphene oxide-silicon metal particle dispersion solution, spray drying is the most preferable. In the case of spray drying, it may be done only once, but in order for the graphene oxide to completely surround the silicon metal particles, two, It is preferable to carry out the spray drying at least three times. At this time, in the spray drying, the graphene oxide-silicon metal particle dispersion solution is sprayed several times, but if necessary, the graphene oxide-silicon metal particle dispersion solution is sprayed, and then the dispersion solution in which only graphene oxide exists is spray-dried to dry the silicon surface. It can also be configured to surround. During spray drying, the water-soluble polymer and water evaporate, leaving only graphene oxide and silicon metal particles to form a powder with a core-shell structure.
또한 산화그래핀-실리콘 금속입자 분산용액을 여러 번 분무건조할 때에 산화그래핀의 사이즈가 상이한 분산용액을 각각 준비한 후, 이를 번갈아가며 분무건조하여 실리콘 금속입자가 외부에 노출되지 않도록 산화그래핀으로 감싸게 된다. 예를 들어 상대적으로 사이즈가 작은 산화그래핀을 포함하는 분산용액을 먼저 분무건조하고 여기에 상대적으로 사이즈가 큰 산화그래핀을 포함하는 분산용액을 분무건조하여 실리콘 금속입자의 표면에 산화그래핀을 코팅할 수 있다. 이와 반대로 상대적으로 사이즈가 큰 산화그래핀을 포함하는 분산용액을 먼저 분무건조 한 후 사이즈가 작은 산화그래핀을 포함하는 분산용액을 분무건조하여도 무방하다.In addition, when the graphene oxide-silicon metal particle dispersion solution is spray-dried several times, dispersion solutions of different sizes of graphene oxide are prepared, respectively, and then spray-dried alternately to prevent the silicon metal particles from being exposed to the outside. will wrap For example, a dispersion solution containing graphene oxide having a relatively small size is first spray-dried, and then a dispersion solution containing graphene oxide having a relatively large size is spray-dried to form graphene oxide on the surface of silicon metal particles. can be coated. Conversely, the dispersion solution containing graphene oxide having a relatively large size may be first spray-dried, and then the dispersion solution containing graphene oxide having a small size may be spray-dried.
산화그래핀-실리콘 금속입자 분말에 광조사하여 환원 및 재결정된 산화그래핀환원물-실리콘 금속입자 복합체를 얻는다(S6a).A reduced and recrystallized graphene oxide-silicon metal particle composite is obtained by irradiating the graphene oxide-silicon metal particle powder with light (S6a).
산화그래핀-실리콘 금속입자 분말 중 산화그래핀을 환원 및 재결정시키기 위해 산화그래핀-실리콘 금속입자 분말에 광조사하여 환원 및 재결정된 산화그래핀환원물-실리콘 금속입자 복합체를 얻는다. 즉 산화그래핀-실리콘 금속입자 분말에 광조사를 하게 되면 광에너지에 의해 산화그래핀이 산화그래핀환원물로 환원되고, 환원과 동시에 산화그래핀 재결정화가 진행되어 우수한 특성을 가지는 산화그래핀환원물-실리콘 금속입자 복합체를 형성하게 된다. In order to reduce and recrystallize graphene oxide in the graphene oxide-silicon metal particle powder, the graphene oxide-silicon metal particle powder is irradiated with light to obtain a reduced and recrystallized graphene oxide reduced product-silicon metal particle composite. That is, when the graphene oxide-silicon metal particle powder is irradiated with light, the graphene oxide is reduced to the graphene oxide reduced product by light energy, and the graphene oxide recrystallization proceeds simultaneously with the reduction to reduce the graphene oxide having excellent properties. A water-silicon metal particle complex is formed.
그래파이트는 그래핀 층이 서로 파이 결합을 통해 층층이 쌓여있는 안정한 상태로 자연계에 존재하는데, 개별 그래핀으로 분리하기 위해서는 앞서 설명한데로 강산을 이용한 산처리를 수행해야한다. 산처리 시 그래파이트의 층 사이로 강산이 침투하게 되면 그래핀간의 파이 결합이 끊어지고 그 자리를 산소기능기(oxygen functional group)들이 결합되는 산화그래파이트가 형성되게 된다. 이때 국부적으로 탄소원자들이 탈락하고 구멍이 형성되어 결함으로 존재하기도 한다. 산소기능기들은 추가적인 환원과정을 통해 떨어져 나갈 수 있지만, 구멍 결함은 일반적인 환원을 통해서는 복구(재결정)되지 않으므로 산화그래핀환원물은 전기전도성이 기존 그래핀보다 우수하지 못하다는 단점이 있다. 따라서 본 발명에서는 광조사를 통해 산화그래핀환원물을 재결정하여 전기전도성이 회복된 산화그래핀환원물을 얻을 수 있게 된다. Graphite exists in nature in a stable state in which graphene layers are stacked layer by layer through pi bonds with each other. When a strong acid penetrates between the layers of graphite during acid treatment, the pi bond between graphene is broken and graphite oxide is formed in which oxygen functional groups are bonded. At this time, carbon atoms are locally dropped and holes are formed, which sometimes exist as defects. Oxygen functional groups can be removed through an additional reduction process, but pore defects are not repaired (recrystallized) through general reduction, so the reduced graphene oxide has a disadvantage that electrical conductivity is not superior to that of conventional graphene. Therefore, in the present invention, it is possible to obtain a graphene oxide reduced product with electrical conductivity recovered by recrystallizing the graphene oxide reduced product through light irradiation.
이때 광조사가 이루어지는 시간은 300밀리초 내지 10분인 것이 바람직하며, 광조사를 통해 산화그래핀의 온도는 상온에서 2500℃까지 상승하게 된다. 광은 300 내지 1,000nm의 파장을 갖는 제논(xenon) 램프을 사용하는데, 제논 램프는 실린더 형상의 밀봉된 석영튜브 안에 주입된 제논 가스를 포함하는 장치로, 전원부로부터 발생된 높은 전원 및 전류를 인가받으면 내부에 주입된 제논 가스가 이온화되면서 강한 세기의 빛이 발생되는 구조로 이루어진다.In this case, it is preferable that the light irradiation time is 300 milliseconds to 10 minutes, and the temperature of graphene oxide is increased from room temperature to 2500° C. through light irradiation. Light uses a xenon lamp having a wavelength of 300 to 1,000 nm. The xenon lamp is a device containing xenon gas injected into a cylindrical sealed quartz tube. It has a structure in which light of strong intensity is generated as the xenon gas injected inside is ionized.
이와 같은 제논 램프로부터 조사되는 극단파 백색광의 펄스폭(pulse width)은 0.1 내지 100ms이고 펄스갭(pulse gap)은 0.1 내지 100ms이며, 펄스수(pulse number)는 1 내지 10,000번이고 에너지밀도(energy density)는 1 내지 300J/㎠인 것이 바람직하다. 이와 같은 펄스폭, 펄스갭, 펄스수 및 에너지밀도가 해당 범위 미만일 경우 광조사를 통한 산화그래핀의 환원이 제대로 이루어지지 않을 수 있으며, 해당 범위를 초과할 경우 너무 강한 광에너지 및 시간으로 인해 실리콘 나노입자가 산화되거나 산화그래핀의 상태가 변할 수 있다.The pulse width of the extreme-wave white light irradiated from such a xenon lamp is 0.1 to 100 ms, and a pulse gap is 0.1 to 100 ms, the pulse number is 1 to 10,000 times, and the energy density (energy) density) is preferably 1 to 300 J/cm 2 . If the pulse width, pulse gap, number of pulses, and energy density are less than the corresponding range, the reduction of graphene oxide through light irradiation may not be performed properly. The nanoparticles may be oxidized or the state of graphene oxide may change.
다음으로 제2실시예에 따른 이와 같은 산화그래핀환원물-실리콘 금속입자 복합체 제조방법은 도 2에 도시된 바와 같이, 제1실시예의 제조방법의 그래파이트를 산화하여 산화그래파이트를 형성하는 단계(S1a), 산화그래파이트를 분산 및 박리하여 산화그래핀을 형성하는 단계(S2a), 양이온-파이 상호작용을 통해 단일층 산화그래핀 분산용액을 제조하는 단계(S3a)와 동일한 S1b 내지 S3b 단계로 이루어져 있어 본 단계의 설명은 생략한다.Next, as shown in FIG. 2, the graphene oxide reduced product-silicon metal particle composite manufacturing method according to the second embodiment comprises the steps of oxidizing the graphite of the manufacturing method of the first embodiment to form graphite oxide (S1a) ), dispersing and exfoliating graphite oxide to form graphene oxide (S2a), and preparing a single-layer graphene oxide dispersion solution through cation-pi interaction (S3a). A description of this step will be omitted.
S3b 단계 이후에, 단일층 산화그래핀 분산용액을 환원시켜 산화그래핀환원물 분산용액을 제조한다(S4b).After step S3b, a single-layer graphene oxide dispersion is reduced to prepare a reduced graphene oxide dispersion (S4b).
양이온반응 단일층 산화그래핀 분산용액을 용매에 중화시킨 후 제조된 용액에 환원제를 첨가하여 습식공정을 통해 환원시킴으로써 산화그래핀 환원물 분산용액을 얻게 된다. 여기서 환원제는 통상적인 환원제를 제한 없이 사용할 수 있으며, 예를 들어 수산화나트륨(NaOH), 수산화칼륨(KOH), 수산화암모늄(NH4OH), 수산화붕소나트륨(NaBH4), 히드라진(N2H4), 하이드로아이오닉산(Hydroionic acid), 아스코빅산(Ascovic acid) 및 이의 혼합으로 이루어진 군으로부터 선택되는 것이 바람직하다.After neutralizing the cationic reaction single-layer graphene oxide dispersion in a solvent, a reducing agent is added to the prepared solution to reduce it through a wet process, thereby obtaining a reduced graphene oxide dispersion. Here, the reducing agent may be a conventional reducing agent without limitation, for example, sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonium hydroxide (NH 4 OH), sodium boron hydroxide (NaBH 4 ), hydrazine (N 2 H 4 ) ), hydroionic acid (Hydroionic acid), ascovic acid (Ascovic acid), and preferably selected from the group consisting of mixtures thereof.
산화그래핀환원물 분산용액을 수용성 폴리머 및 실리콘 금속입자와 혼합하여 산화그래핀환원물-실리콘 금속입자 분산용액을 제조한다(S5b).A reduced graphene oxide dispersion solution is mixed with a water-soluble polymer and silicon metal particles to prepare a reduced graphene oxide-silicon metal particle dispersion solution (S5b).
S4b 단계를 통해 제조된 산화그래핀환원물 분산용액을 수용성 폴리머 및 실리콘 금속입자와 혼합하여 산화그래핀환원물-실리콘 금속입자 분산용액을 제조한다. 산화그래핀환원물 분산용액의 경우 물을 포함하고 있으나 산화그래핀환원물 및 실리콘 금속입자는 물에 골고루 분산되지 않는다는 단점이 있다. 따라서 산화그래핀환원물과 실리콘 금속입자가 물에서 분산성이 우수하도록 수용성 폴리머를 추가하여 혼합하고, 이를 통해 산화그래핀환원물-실리콘 금속입자 분산용액을 제조한다. 여기서 수용성 폴리머는 제1실시예와 동일한 폴리머를 사용 가능하다.The graphene oxide reduced product dispersion solution prepared in step S4b is mixed with a water-soluble polymer and silicon metal particles to prepare a graphene oxide reduced product-silicon metal particle dispersion solution. Although the graphene oxide reduced product dispersion solution contains water, there is a disadvantage that the graphene oxide reduced product and silicon metal particles are not evenly dispersed in water. Therefore, a water-soluble polymer is added and mixed so that the graphene oxide reduced product and the silicon metal particles have excellent dispersibility in water, and through this, a graphene oxide reduced product-silicon metal particle dispersion solution is prepared. Here, as the water-soluble polymer, the same polymer as in the first embodiment may be used.
산화그래핀환원물-실리콘 금속입자 분산용액을 건조하여 코어-쉘 구조의 분말을 제조한다(S6b).The reduced graphene oxide-silicon metal particle dispersion solution is dried to prepare a powder having a core-shell structure (S6b).
S5b 단계를 통해 제조된 산화그래핀환원물-실리콘 금속입자 분산용액을 건조The graphene oxide reduced product-silicon metal particle dispersion solution prepared through step S5b was dried
하여 실리콘 금속입자는 코어(core)로 내부에 존재하고 산화그래핀환원물은 실리콘 금속입자의 주위를 둘러싸는 형태의 외부 쉘(shell) 구조로 이루어진 코어-쉘 구조의 복합체 분말을 제조한다. 이때 산화그래핀환원물-실리콘 금속입자 분산용액을 건조하는 방법으로는 제1실시예와 마찬가지로 분무건조가 가장 바람직하나 이에 한정되지는 않는다. Thus, a core-shell structure composite powder is prepared in which the silicon metal particles exist as a core and the graphene oxide reduced product has an outer shell structure surrounding the silicon metal particles. At this time, as a method of drying the graphene oxide reduced product-silicon metal particle dispersion solution, spray drying is most preferable as in the first embodiment, but is not limited thereto.
산화그래핀환원물-실리콘 금속입자 분말에 광조사하여 재결정된 산화그래핀환원물-실리콘 금속입자 복합체를 얻는다(S7b).A reduced graphene oxide-silicon metal particle powder is irradiated with light to obtain a recrystallized graphene oxide reduced product-silicon metal particle composite (S7b).
산화그래핀환원물-실리콘 금속입자 분말 중 산화그래핀환원물을 재결정하기 위해 산화그래핀환원물-실리콘 금속입자 분말에 광조사하여 재결정된 산화그래핀환원물-실리콘 금속입자 복합체를 얻는다. 제1실시예와는 달리 제2실시예는 이미 환원되어진 산화그래핀환원물을 포함하기 때문에 본 단계에서는 산화그래핀환원물의 재결정만 이루어지게 된다. 산화그래핀환원물-실리콘 금속입자 분말에 광조사를 하게 되면 광에너지에 의해 산화그래핀환원물이 재결정되어 우수한 특성을 가지는 산화그래핀환원물-실리콘 금속입자 복합체를 형성하게 된다.In order to recrystallize the graphene oxide reduced product-silicon metal particle powder, the graphene oxide reduced product-silicon metal particle powder is irradiated with light to obtain a recrystallized graphene oxide reduced product-silicon metal particle composite. Unlike the first embodiment, since the second embodiment includes the reduced graphene oxide reduced product, only the recrystallization of the graphene oxide reduced product is performed in this step. When the graphene oxide reduced product-silicon metal particle powder is irradiated with light, the graphene oxide reduced product is recrystallized by light energy to form a graphene oxide reduced product-silicon metal particle composite having excellent properties.
이때 광조사 조건은 제1실시예와 동일하게 이루어질 수 있다.In this case, the light irradiation conditions may be the same as those of the first embodiment.
이하에서는 본 발명의 실시예를 좀 더 상세하게 설명한다.Hereinafter, embodiments of the present invention will be described in more detail.
<실시예 1> : 광조사를 통한 산화그래핀 환원물-실리콘 금속입자 복합체 제조<Example 1>: Preparation of reduced graphene oxide-silicon metal particle composite through light irradiation
1-1. 산화그래핀 제조1-1. Graphene Oxide Manufacturing
그래파이트(순도 99.9995%, -200메쉬) 10g, 발연질산 350ml 및 소듐클로레이트(NaClO4) 74g을 실온에서 순차적으로 37g씩 나누어 혼합한다. 혼합물을 48시간 동안 교반한 후, 중화 및 세척 과정을 거치고 여과, 클리닝, 건조 과정을 순차적으로 거쳐 산화그래핀을 제조한다. 산화그래핀은 300mg/L 농도로 수산화칼륨(KOH) 용액에 호모게나이저를 15,000rpm으로 1시간 동안 처리하여 산화그래핀 분산용액을 제조한다. 양이온-파이 상호작용을 인가시키기 위해서 상온에서 산화그래핀 분산용액의 반응시간을 1시간 이상 유지한다.Graphite (99.9995% purity, -200 mesh) 10g, fuming nitric acid 350ml and sodium chlorate (NaClO 4 ) 74g 37g sequentially divided and mixed at room temperature. After the mixture is stirred for 48 hours, it undergoes neutralization and washing processes, followed by filtration, cleaning, and drying processes to prepare graphene oxide. Graphene oxide was treated with a homogenizer in potassium hydroxide (KOH) solution at a concentration of 300 mg/L at 15,000 rpm for 1 hour to prepare a graphene oxide dispersion solution. In order to apply the cation-pi interaction, the reaction time of the graphene oxide dispersion solution at room temperature is maintained for 1 hour or more.
1-2. 산화그래핀-실리콘 금속입자 분말 제조1-2. Graphene oxide-silicon metal particle powder production
실시예 1-1의 산화그래핀 분산용액에 10 내지 20㎛ 사이즈의 실리콘 금속입자를 혼합하여 500rpm으로 stirring한다. 이후 소듐카르복시메틸셀룰로오스(sodium carboxymethyl cellulose)를 3wt% 첨가하여 분산한다. 분산된 산화그래핀-실리콘 금속입자 분산용액을 분무건조하여 분말을 제조한다.Silicon metal particles having a size of 10 to 20 μm were mixed in the graphene oxide dispersion solution of Example 1-1 and stirred at 500 rpm. After that, 3 wt% of sodium carboxymethyl cellulose is added and dispersed. The dispersed graphene oxide-silicon metal particle dispersion solution is spray-dried to prepare a powder.
1-3. 산화그래핀환원물-실리콘 금속입자 복합체 제조1-3. Graphene oxide reduced product-silicon metal particle composite production
실시예 1-2의 산화그래핀-실리콘 금속입자 분말을 9.6J/㎠의 제논램프로 조사하여 산화그래핀을 환원시킴과 동시에 재결정하여 산화그래핀환원물-실리콘 금속입자 복합체를 제조한다.The graphene oxide-silicon metal particle powder of Example 1-2 was irradiated with a xenon lamp of 9.6 J/cm 2 to reduce graphene oxide and recrystallize at the same time to prepare a reduced graphene oxide-silicon metal particle composite.
<실시예 2> : 광조사를 통한 산화그래핀환원물-실리콘 금속입자 복합체 제조<Example 2>: Preparation of reduced graphene oxide-silicon metal particle composite through light irradiation
2-1. 산화그래핀 제조2-1. Graphene Oxide Manufacturing
그래파이트(순도 99.9995%, -200메쉬) 10g, 발연질산 350ml 및 소듐클로레이트(NaClO4) 74g을 실온에서 순차적으로 37g씩 나누어 혼합한다. 혼합물을 48시간 동안 교반한 후, 중화 및 세척 과정을 거치고 여과, 클리닝, 건조 과정을 순차적으로 거쳐 산화그래핀을 제조한다. 산화그래핀은 300mg/L 농도로 수산화칼륨(KOH) 용액에 호모게나이저를 15,000rpm으로 1시간 동안 처리하여 산화그래핀 분산용액을 제조한다. 양이온-파이 상호작용을 인가시키기 위해서 상온에서 산화그래핀 분산용액의 반응시간을 1시간 이상 유지한다.Graphite (99.9995% purity, -200 mesh) 10g, fuming nitric acid 350ml and sodium chlorate (NaClO 4 ) 74g 37g sequentially divided and mixed at room temperature. After the mixture is stirred for 48 hours, it undergoes neutralization and washing processes, followed by filtration, cleaning, and drying processes to prepare graphene oxide. Graphene oxide was treated with a homogenizer in potassium hydroxide (KOH) solution at a concentration of 300 mg/L at 15,000 rpm for 1 hour to prepare a graphene oxide dispersion solution. In order to apply the cation-pi interaction, the reaction time of the graphene oxide dispersion solution at room temperature is maintained for 1 hour or more.
2-2. 산화그래핀환원물-실리콘 금속입자 분말 제조2-2. Graphene oxide reduced product-silicon metal particle powder production
실시예 2-1의 산화그래핀 분산용액에 10 내지 20㎛ 사이즈의 실리콘 금속입자를 혼합하여 500rpm으로 stirring한다. 이후 소듐카르복시메틸셀룰로오스(sodium carboxymethyl cellulose) 1wt% 및 요오드화수소산(HI acid) 40㎕를 넣고 60℃에서 10시간 동안 교반하여 분산 및 환원시킨다. 분산된 산화그래핀환원물-실리콘 금속입자 분산용액을 분무건조하여 분말을 제조한다.Silicon metal particles having a size of 10 to 20 μm were mixed with the graphene oxide dispersion solution of Example 2-1 and stirred at 500 rpm. After that, 1 wt% of sodium carboxymethyl cellulose and 40 μl of hydroiodic acid (HI acid) were added and stirred at 60° C. for 10 hours to disperse and reduce. The dispersed graphene oxide reduced product-silicon metal particle dispersion solution is spray-dried to prepare a powder.
2-3. 산화그래핀환원물-실리콘 금속입자 복합체 제조2-3. Graphene oxide reduced product-silicon metal particle composite production
실시예 2-2의 산화그래핀환원물-실리콘 금속입자 분말을 9.6J/㎠의 제논램프로 조사하여 산화그래핀환원물을 재결정하여 산화그래핀환원물-실리콘 금속입자 복합체를 제조한다.The graphene oxide reduced product of Example 2-2 - silicon metal particle powder was irradiated with a xenon lamp of 9.6 J/cm 2 to recrystallize the graphene oxide reduced product to prepare a graphene oxide reduced product-silicon metal particle composite.
<비교예 1> : 환원제를 통한 산화그래핀환원물-실리콘 금속입자 복합체 제조<Comparative Example 1>: Graphene oxide reduced product-silicon metal particle composite production through a reducing agent
1-1. 산화그래핀 제조1-1. Graphene Oxide Manufacturing
실시예와 동일하게 그래파이트(순도 99.9995%, -200메쉬) 10g, 발연질산 350ml 및 소듐클로레이트(NaClO4) 74g을 실온에서 순차적으로 37g씩 나누어 혼합한다. 혼합물을 48시간 동안 교반한 후, 중화 및 세척 과정을 거치고 여과, 클리닝, 건조 과정을 순차적으로 거쳐 산화그래핀을 제조한다. 산화그래핀은 300mg/L 농도로 수산화칼륨(KOH) 용액에 호모게나이저를 15,000rpm으로 1시간 동안 처리하여 산화그래핀 분산용액을 제조한다. 양이온-파이 상호작용을 인가시키기 위해서 상온에서 산화그래핀 분산용액의 반응시간을 1시간 이상 유지한다.In the same manner as in Example, 10 g of graphite (99.9995% purity, -200 mesh), 350 ml of fuming nitric acid and 74 g of sodium chlorate (NaClO 4 ) are sequentially divided and mixed at room temperature by 37 g each. After the mixture is stirred for 48 hours, it undergoes neutralization and washing processes, followed by filtration, cleaning, and drying processes to prepare graphene oxide. Graphene oxide was treated with a homogenizer in potassium hydroxide (KOH) solution at a concentration of 300 mg/L at 15,000 rpm for 1 hour to prepare a graphene oxide dispersion solution. In order to apply the cation-pi interaction, the reaction time of the graphene oxide dispersion solution at room temperature is maintained for 1 hour or more.
1-2. 산화그래핀환원물 제조1-2. Manufacture of reduced graphene oxide
비교예 1-1의 산화그래핀 분산용액(1g/L)에 소듐카르복시메틸셀룰로오스(sodium carboxymethyl cellulose) 1wt%와 요오드화수소산(HI acid) 40㎕를 넣고 60℃에서 10시간 동안 교반하여 산화그래핀환원물을 제조한다. 이후 수산화칼륨(KOH)을 첨가하고 교반 후, 원심분리를 통해 과량의 요오드화수소산을 제거한다.1 wt% of sodium carboxymethyl cellulose and 40 μl of hydroiodic acid (HI acid) were added to the graphene oxide dispersion solution (1 g/L) of Comparative Example 1-1, and stirred at 60 ° C. for 10 hours. Prepare a reduced product. After adding potassium hydroxide (KOH) and stirring, excess hydroiodic acid is removed by centrifugation.
1-3. 산화그래핀환원물-실리콘 금속입자 복합체 제조1-3. Graphene oxide reduced product-silicon metal particle composite production
비교예 102의 산화그래핀환원물 분산용액에 10 내지 20㎛ 사이즈의 실리콘 금속입자를 혼합하여 500rpm으로 stirring한다. 분산된 산화그래핀환원물-실리콘 금속입자 분산용액을 분무건조하여 분말을 제조한다.Silicon metal particles having a size of 10 to 20 μm were mixed in the graphene oxide reduced product dispersion solution of Comparative Example 102 and stirred at 500 rpm. The dispersed graphene oxide reduced product-silicon metal particle dispersion solution is spray-dried to prepare a powder.
<비교예 2> 아세틸렌블랙(acetylene black)-실리콘 금속입자 복합체 제조<Comparative Example 2> Preparation of acetylene black-silicon metal particle composite
아세틸렌블랙 분말과 실리콘 금속입자 분말을 1:1 질량비로 혼합하고 증류수를 이용하여 분산한 후, 분무건조하여 아세틸렌블랙-실리콘 금속입자 복합체를 제조한다.Acetylene black powder and silicon metal particle powder are mixed in a 1:1 mass ratio, dispersed using distilled water, and then spray-dried to prepare an acetylene black-silicon metal particle composite.
도 3은 실시예 1에 의해 제조된 산화그래핀환원물-실리콘 금속입자 복합체의 주사전자현미경 사진이고, 도 4는 비교예 1에 의해 제조된 산화그래핀환원물-실리콘 금속입자 복합체의 주사전자현미경 사진이다.3 is a scanning electron microscope photograph of the graphene oxide reduced product-silicon metal particle composite prepared in Example 1, and FIG. 4 is a graphene oxide reduced product prepared by Comparative Example 1 - Scanning electrons of the silicon metal particle composite It is a photomicrograph.
도 5는 실시예 1 및 비교예 1에 의해 제조된 산화그래핀환원물-실리콘 금속입자 복합체의 라만스펙트럼을 나타낸 것으로, 실시예 1은 재결정이 이루어짐에 의해 결정성이 증가된 것을 확인할 수 있다.5 shows the Raman spectrum of the graphene oxide reduced product-silicon metal particle composite prepared by Example 1 and Comparative Example 1, and it can be confirmed that the crystallinity of Example 1 is increased by recrystallization.
도 6은 실시예 및 비교예에 의해 제조된 산화그래핀환원물-실리콘 금속입자 복합체 및 아세틸렌블랙-실리콘 금속입자 복합체의 임피던스 그래프를 나타낸 것이다. 임피던스 그래프의 경우 측정값을 통해 그려지는 반원폭이 클수록 저항이 크다는 것을 의미한다. 비교예 2의 경우 그 반원폭이 매우 큰 것을 확인할 수 있으며, 이는 저항이 크다는 것을 의미한다. 또한 비교예 1의 경우 비교예 2보다는 반원폭이 작으나 실시예 1보다는 큰 것을 알 수 있다. 즉 본 발명과 같이 광조사를 통해 재결정된 산화그래핀환원물을 형성할 경우 저항이 낮아져 전기전도도가 우수해지는 것을 알 수 있다.6 shows an impedance graph of the graphene oxide reduced product-silicon metal particle composite and acetylene black-silicon metal particle composite prepared by Examples and Comparative Examples. In the case of the impedance graph, the larger the half-width drawn through the measured value, the greater the resistance. In the case of Comparative Example 2, it can be seen that the semi-atomic width is very large, which means that the resistance is large. In addition, in the case of Comparative Example 1, it can be seen that the semi-atomic width is smaller than that of Comparative Example 2, but larger than that of Example 1. That is, it can be seen that when the reduced graphene oxide recrystallized through light irradiation is formed as in the present invention, the resistance is lowered and the electrical conductivity is improved.
도 7은 실시예 및 비교예에 따른 복합체의 전기화학특성 그래프를 나타낸 것이다. 이는 충방전 횟수에 따른 전기화학특성을 확인하는 것으로 초기값 대비 비교예 1 및 2의 경우 충방전 용량이 급격하게 줄어드는 것에 비해 실시예 1의 경우 비교예보다는 완만하게 용량이 줄어드는 것을 확인할 수 있다. 즉 실시예 1은 비교예에 비해 전지 수명이 길어진다는 것을 의미한다.7 shows graphs of electrochemical properties of composites according to Examples and Comparative Examples. This is to confirm the electrochemical characteristics according to the number of charge and discharge, compared to the initial value in Comparative Examples 1 and 2, the charge and discharge capacity is abruptly reduced, but in the case of Example 1, it can be confirmed that the capacity is reduced more gently than the comparative example. That is, Example 1 means that the battery life is longer than that of Comparative Example.
Claims (10)
상기 그래핀-실리콘 금속입자 분말에 광조사하여 산화그래핀환원물-실리콘 금속입자 복합체를 얻는 단계;를 포함하되,
상기 산화그래핀환원물-실리콘 금속입자 복합체는, 상기 광조사를 통하여 상기 그래핀이 상기 산화그래핀환원물로 환원됨과 동시에 재결정되어 전기전도도가 우수한 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체 제조방법.By spray-drying a graphene dispersion solution formed through cation-pi interaction, a dispersion solution in which a water-soluble polymer and silicon metal particles are mixed, the silicon metal particle is the core, and the graphene is formed into a shell surrounding the silicon metal particle to be, core-shell structure graphene-preparing a silicon metal particle powder; and
The graphene-silicon metal particle powder is irradiated with light to obtain a graphene oxide reduced product-silicon metal particle composite; including,
The graphene oxide reduced product-silicon metal particle composite is formed through light irradiation, characterized in that the graphene is reduced to the graphene oxide reduced product and recrystallized at the same time through the light irradiation, which is characterized in that it has excellent electrical conductivity. A method for manufacturing a pin-reduced product-silicon metal particle composite.
상기 그래핀은 산화그래핀이며,
상기 그래핀-실리콘 금속입자 분말을 제조하는 단계는,
그래파이트를 산화하여 산화그래파이트를 형성하는 단계;
상기 산화그래파이트를 분산 및 박리하여 산화그래핀을 형성하는 단계;
상기 양이온-파이 상호작용을 통해 상기 산화그래핀을 포함하는 산화그래핀 분산용액을 제조하는 단계;
상기 산화그래핀 분산용액을 상기 수용성 폴리머 및 상기 실리콘 금속입자와 혼합하여 산화그래핀-실리콘 금속입자 분산용액을 제조하는 단계; 및
상기 산화그래핀-실리콘 금속입자 분산용액을 분무건조하여 상기 수용성 폴리머와 물은 증발되고 코어-쉘 구조의 복합체 분말을 제조하는 단계;를 포함하고,
상기 광조사를 통해 상기 산화그래핀이 환원됨과 동시에 재결정되는 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체 제조방법.The method of claim 1,
The graphene is graphene oxide,
The step of preparing the graphene-silicon metal particle powder,
oxidizing graphite to form graphite oxide;
dispersing and exfoliating the graphite oxide to form graphene oxide;
preparing a graphene oxide dispersion solution containing the graphene oxide through the cation-pi interaction;
mixing the graphene oxide dispersion solution with the water-soluble polymer and the silicon metal particles to prepare a graphene oxide-silicon metal particle dispersion solution; and
The graphene oxide-silicon metal particle dispersion solution is spray-dried to evaporate the water-soluble polymer and water to prepare a composite powder having a core-shell structure;
The graphene oxide reduced material formed through light irradiation, characterized in that the graphene oxide is reduced and recrystallized at the same time through the light irradiation - a method for producing a silicon metal particle composite.
상기 그래핀은 산화그래핀환원물이며,
상기 그래핀-실리콘 금속입자 분말을 제조하는 단계는,
그래파이트를 산화하여 산화그래파이트를 형성하는 단계;
상기 산화그래파이트를 분산 및 박리하여 산화그래핀을 형성하는 단계;
상기 양이온-파이 상호작용을 통해 상기 산화그래핀을 포함하는 산화그래핀 분산용액을 제조하는 단계;
상기 산화그래핀 분산용액을 환원시켜 산화그래핀환원물 분산용액을 제조하는 단계;
상기 산화그래핀환원물 분산용액을 상기 수용성 폴리머 및 상기 실리콘 금속입자와 혼합하여 산화그래핀환원물-실리콘 금속입자 분산용액을 제조하는 단계; 및
상기 산화그래핀환원물-실리콘 금속입자 분산용액을 분무건조하여 상기 수용성 폴리머와 물은 증발되고 코어-쉘 구조의 복합체 분말을 제조하는 단계;를 포함하는 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체 제조방법.The method of claim 1,
The graphene is a reduced graphene oxide,
The step of preparing the graphene-silicon metal particle powder,
oxidizing graphite to form graphite oxide;
dispersing and exfoliating the graphite oxide to form graphene oxide;
preparing a graphene oxide dispersion solution containing the graphene oxide through the cation-pi interaction;
reducing the graphene oxide dispersion to prepare a reduced graphene oxide dispersion;
mixing the reduced graphene oxide dispersion solution with the water-soluble polymer and the silicon metal particles to prepare a reduced graphene oxide-silicon metal particle dispersion solution; and
The reduced graphene oxide-silicon metal particle dispersion solution is spray-dried to evaporate the water-soluble polymer and water to prepare a composite powder having a core-shell structure; oxidation formed through light irradiation, comprising: Graphene reduced product-silicon metal particle composite manufacturing method.
상기 산화그래파이트를 형성하는 단계는,
그래파이트 플레이크를 산처리를 통해 합성하고,
상기 산처리는 상기 그래파이트 플레이크에 농질산(fuming nitric acid) 또는 황산(sulfuric acid)에 소듐클로레이트(NaClO4) 또는 포타슘퍼망가네이트(KMnO4)를 첨가하여 교반을 통해 이루어지는 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체 제조방법.4. The method of claim 2 or 3,
The step of forming the graphite oxide,
Graphite flakes are synthesized through acid treatment,
The acid treatment is carried out by adding sodium chlorate (NaClO 4 ) or potassium permanganate (KMnO 4 ) to fuming nitric acid or sulfuric acid to the graphite flakes, characterized in that through stirring, light A method for producing a graphene oxide reduced product-silicon metal particle composite formed through irradiation.
상기 산화그래핀 분산용액을 제조하는 단계는,
상기 산화그래핀을 알칼리 용매에 분산 및 박리하여 산화그래핀 분산용액을 형성하는 단계; 및
상기 산화그래핀 분산용액 내에 탄소 원자들이 2차원 상에서 sp2결합에 의해 연결된 배열의 중심에 양이온을 위치시킴에 의해, 양이온과 sp2영역의 파이구조와의 양이온-파이 상호작용을 통해 양이온반응 산화그래핀 분산용액을 제조하는 단계;를 포함하는 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체 제조방법.4. The method of claim 2 or 3,
The step of preparing the graphene oxide dispersion solution,
dispersing and exfoliating the graphene oxide in an alkaline solvent to form a graphene oxide dispersion solution; and
By locating cations at the center of an arrangement in which carbon atoms are connected by sp 2 bonds in two dimensions in the graphene oxide dispersion solution, cation-reaction oxidation with cations and pi structures of sp 2 regions through cation-pi interaction Preparing a graphene dispersion solution; characterized in that it comprises, graphene oxide reduced product formed through light irradiation-silicon metal particle composite manufacturing method.
상기 산화그래핀 분산용액을 제조하는 단계는,
상기 산화그래핀환원물과 상기 실리콘 금속입자가 물에서 분산성이 우수하도록 상기 수용성 폴리머를 추가하여 혼합하는 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체 제조방법.4. The method of claim 2 or 3,
The step of preparing the graphene oxide dispersion solution,
The reduced graphene oxide and the silicon metal particle, characterized in that the water-soluble polymer is added and mixed so that the silicon metal particle has excellent dispersibility in water, the reduced graphene oxide formed through light irradiation - a method for producing a silicon metal particle composite.
상기 광조사는,
파장이 300 내지 1,000nm, 펄스폭(pulse width)은 0.1 내지 100ms, 펄스갭(pulse gap)은 0.1 내지 100ms, 펄스수(pulse number)는 1 내지 10,000번, 에너지밀도(energy density)는 1 내지 300J/㎠인 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체 제조방법.The method of claim 1,
The light irradiation is
The wavelength is 300 to 1,000 nm, the pulse width is 0.1 to 100 ms, the pulse gap is 0.1 to 100 ms, the pulse number is 1 to 10,000 times, and the energy density is 1 to 100 ms. 300J/cm2, characterized in that the graphene oxide reduced product formed through light irradiation-silicon metal particle composite manufacturing method.
상기 산화그래핀환원물-실리콘 금속입자 복합체는, 상기 광조사를 통하여 상기 그래핀이 상기 산화그래핀환원물로 환원됨과 동시에 재결정되어 전기전도도가 우수한 것을 특징으로 하는, 광조사를 통해 형성된 산화그래핀환원물-실리콘 금속입자 복합체.By spray-drying a graphene dispersion solution formed through cation-pi interaction, a dispersion solution in which a water-soluble polymer and silicon metal particles are mixed, the silicon metal particle is the core, and the graphene is formed into a shell surrounding the silicon metal particle As a graphene oxide-reduced product-silicon metal particle composite formed by irradiating light to the graphene-silicon metal particle powder of the core-shell structure,
The graphene oxide reduced product-silicon metal particle composite is formed through light irradiation, characterized in that the graphene is reduced to the graphene oxide reduced product and recrystallized at the same time through the light irradiation, which is characterized in that it has excellent electrical conductivity. A pin-reduced product-silicon metal particle complex.
상기 집전체의 일면에 형성되고 산화그래핀환원물-실리콘 금속입자 복합체를 갖는 활물질;로 이루어지며,
상기 산화그래핀환원물-실리콘 금속입자 복합체는,
양이온-파이 상호작용을 통해 형성된 그래핀 분산용액, 수용성 폴리머 및 실리콘 금속입자를 혼합한 분산용액을 분무건조하여, 상기 실리콘 금속입자가 코어이고, 상기 그래핀이 상기 실리콘 금속입자를 둘러싸는 쉘로 형성되는, 코어-쉘 구조의 그래핀-실리콘 금속입자 분말에 광조사하여 형성되는 것이되,
상기 광조사를 통하여 상기 그래핀이 상기 산화그래핀환원물로 환원됨과 동시에 재결정되어 전기전도도가 우수한 것을 특징으로 하는, 이차전지용 전극.current collector; and
Formed on one surface of the current collector and graphene oxide reduced material-active material having a silicon metal particle complex; consists of,
The graphene oxide reduced product-silicon metal particle composite,
By spray-drying a graphene dispersion solution formed through cation-pi interaction, a dispersion solution in which a water-soluble polymer and silicon metal particles are mixed, the silicon metal particle is the core, and the graphene is formed into a shell surrounding the silicon metal particle The core-shell structure graphene-silicon metal particle powder is formed by irradiating light,
The electrode for a secondary battery, characterized in that the graphene is reduced to the reduced graphene oxide through the light irradiation and recrystallized at the same time to have excellent electrical conductivity.
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