Abstract:
The purpose of the present invention is to provide a manufacturing method of a lithium iron phosphate cathode active material, a lithium iron phosphate cathode active material manufactured thereby, and a secondary battery manufactured using the same. The present invention provides a manufacturing method of a lithium iron phosphate cathode active material, which comprises a step of manufacturing a mixed solution by mixing a lithium precursor, an iron precursor and a phosphate precursor at 2.5-3.5:1:1.5-2.5 of the mole ratio, and dissolving in a solvent including a dispersant (step 1); and a step of heating the mixed solution of step 1 by using microwaves. Further, the present invention provides a crystalline lithium iron phosphate cathode active material, which is manufactured by the manufacturing method, and comprises first particles having a particle size of 30-200 nm, and second particles having a particle size of 1-5 μm, wherein the second particles include multiple first particles, and have a spherical shape. The present invention provides a crystalline lithium iron phosphate cathode active material, which is manufactured by the manufacturing method, and comprises first particles having a particle size of 50-400 nm, and second particles having a particle size of 1-5 μm, wherein the second particles include multiple first particles, and have a rod shape. The lithium iron phosphate cathode active material manufactured according to the present invention consists of first particles with a nanometer size, and second particles with a micrometer size, thereby enhancing the electric conductivity, increasing the energy density per volume, and improving the electrode manufacture processibilty. Furthermore, the lithium iron phosphate cathode active material can enhance the performance by improving the size and coagulation of particles by adjusting the mixing ratio of raw materials.
Abstract:
본 발명은 다공성 실리카를 이용한 녹색 형광체의 제조방법 및 이에 따라 제조되는 녹색 형광체에 관한 것으로, 상세하게는 산(acid), 증류수 및 유기용매를 혼합한 후, 아연 전구체, 망간 전구체, 겔화 작용제 및 에틸렌글리콜을 첨가하고 교반하여 겔(gel)을 제조하는 단계(단계 1); 상기 단계 1에서 제조된 겔로 다공성 실리카를 첨가하고 교반하여 겔 함유 다공성 실리카를 제조하는 단계(단계 2); 상기 단계 2에서 제조된 겔 함유 다공성 실리카를 건조한 후, 1000 내지 1200 ℃의 온도인 산화분위기에서 1 내지 3 시간 동안 소성하는 단계(단계 3); 및 상기 단계 3의 소성이 수행된 아연 및 망간을 포함하는 다공성 실리카를 700 내지 900 ℃의 온도인 환원분위기에서 1 내지 3 시간 동안 환원처리하는 단계(단계 4)를 포함하는 다공성 실리카를 이용한 녹색 형광체의 제조방법을 제공한다. 본 발명에 따른 다공성 실리카를 이용한 녹색 형광체의 제조방법을 통해 구형의 형태를 나타내고, 100 nm 이하의 직경인 녹색 형광체 입자를 제조할 수 있으며, 제조된 녹색 형광체는 종래의 코어-쉘 형태로 제조되는 형광체와 비교하여 입자 크기, 입도 분포, 발광 휘도 등의 면에서 더욱 우수하다. 또한, 제조된 녹색 형광체는 특정 용매에 분산시킨 후 투명기판 상에 스핀코팅, 잉크젯 코팅 방법 등을 통하여 형광막을 형성시킬 수 있어 자발광형 투명 디스플레이의 발광재료로서 이용될 수 있다.
Abstract:
PURPOSE: A manufacturing method of monodispersed spherical red phosphor is provided to embody short persistent property in ultraviolet excitation light source, and to manufacture red fluorescent material which has spherical particle shape and uniform particle size distribution. CONSTITUTION: A manufacturing method of the red-emitting phosphor comprises: a step of manufacturing precursor mixed solution by dissolving yttrium precursor, gadolinium precursor, boron precursor, europium precursor and sodium oleate into distilled water; a step of manufacturing mixed solution by adding benzyl alcohol and oleic acid into the precursor mixed solution; and a step of solvothermal reacting the mixed solution at 200-230 °C for 6-12 hours; and a step of manufacturing powder particles by centrifuge process and drying process of the solution.