1. 연구의 목적 전기구동의 소형 PRT (Personal Rapid Transit, 무인자동궤도 운행차량)의 전원으로서 슈퍼커패시터의 출력특성과 이차전지의 에너지저장 특성을 겸비한 융합형 에너지저장 디바이스를 개발함 ...
1. 연구의 목적 전기구동의 소형 PRT (Personal Rapid Transit, 무인자동궤도 운행차량)의 전원으로서 슈퍼커패시터의 출력특성과 이차전지의 에너지저장 특성을 겸비한 융합형 에너지저장 디바이스를 개발함
2. 연구 내용 1) 하이브리드 커패시터 설계 양극에 Ni(OH)2 활물질과 음극에 활성탄을 사용하는 하이브리드 커패시터 (hybrid capacitor)와 양극에 Ni(OH)2 활물질과 음극에 수소흡장재료인 metal alloy를 사용하는 NiMH 이차전지를 혼합한 고에너지 하이브리드 커패시터 (양극 : Ni(OH)2, 음극 : LaNi5, 활성탄)를 설계하고 제조함
2) 소재 및 전극 요소기술 개발 - 양극 활물질인 Ni(OH)2는 합성법에 의해 GO (Graphite Oxide)에 나노 분산된 nano-Ni(OH)2 복합 소재를 제조하였으며 μm 크기의 구상 분말형성을 위해 spray drying 공정을 사용하였음
- 양, 음극 전극은 Ni foam을 이용하여 활물질, 바인더 및 카본블랙 등을 혼합한 슬러리를 dip coating 공정을 이용하여 0.6∼1.0mm 두께의 후박형 전극을 제조함
3) 셀 특성 향상 기술 개발 - Ni(OH)2 활물질의 전도성 향상 및 formation 시간 단축을 위해 양극에 CoO를 소량 첨가하여 도전성 착이온과 표면 도전성 네트워크를 형성하였으며, initial charging step (0.01C×5hr, 0.02C×5hr, 0.05C×5hr)을 개발함
- 친수성 특성 향상을 위해 활성탄의 표면은 산처리 및 고온 열처리에 의해 표면 산성관능기를 형성시겼으며, 전극의 Co-binder additive (PVA)를 첨가하여 전극의 결착력 및 wettability 특성을 향상시킴
- 셀의 온도특성을 향상시키기 위해 KOH, LiOH 및 NaOH로 구성된 혼합 알칼리 수계 전해액을 개발하여 –30℃에서 65℃까지 대응이 가능하도록 함
4) 셀 특성 평가 연구 - 단위 셀의 전압은 1.5V, 에너지밀도는 90Wh/L, 파워밀도는 4,100W/L, 충방전 cycle은 82%@20,000 cycle, 온도특성은 –30∼65℃에서 80% 이상을 나타냄
- 양산공정에 적용한 시제품 특성은 1.5V-25Ah를 나타냄
(출처 : 보고서 초록 3p)
Abstract ▼
Ⅱ. Purpose and Necessity of R & D ∘ It is necessary to develop an electric PRT (Personal Rapid Transit) for the network route o...
Ⅱ. Purpose and Necessity of R & D ∘ It is necessary to develop an electric PRT (Personal Rapid Transit) for the network route operation as an advanced public transportation means to provide convenient facilities for the transportation weak.
∘ Supercapacitors and lithium-ion batteries have been developed as energy storage power sources for electric vehicles, but the former have a low energy density and the latter have a disadvantage in that they lack output and long-term reliability.
∘ In this project, we developed a convergent energy storage power source that combines the output characteristics of a supercapacitor and the energy characteristics of a secondary battery as an energy storage power source for electric vehicles.
Ⅲ. Contents and Scope of R & D ∘ Design of hybrid capacitor High-energy hybrid capacitor designed by mixing a hybrid capacitor (using Ni(OH)2 active material on the cathode and activated carbon on the anode) and NiMH (using Ni(OH)2 active material on the cathode and metal alloy as the hydrogen storage material on the anode) was developed.
∘ Development of active material and electrode element technology - Ni(OH)2, a cathode active material, was prepared by nano-dispersed Ni(OH)2 composite material on GO (Graphite Oxide) and spray drying process was used for forming spherical powder having μm size.
- The cathode and anode electrodes were prepared by dip coating process using a slurry containing active material, binder and carbon black, and the thickness of Ni-foam based electrodes were adjusted within the range of 0.6 to 1.0mm.
∘ Development study on improvement of cell characteristics - In order to improve the conductivity and shorten the formation time of Ni(OH)2 active material, a small amount of CoO was added to the cathode to form a conductive complex ion and surface conductive network. The initial charging step (0.01C × 5hr, 0.02C × 5hr, 5hr) was developed.
- Surface acidic functional groups were formed by surface acid treatment and high-temperature heat treatment of activated carbon to improve the hydrophilic property. Co-binder additive (PVA) of the electrode was added to improve the adhesion and wettability of the electrode.
- To improve the temperature characteristics of cells capable of operating from –30℃ to 65℃, a mixed alkaline aqueous electrolyte consisting of KOH, LiOH and NaOH was developed.
∘ Evaluation of cell characteristics - The unit cell voltage is 1.5V, the energy density is 90Wh/L, the power density is 4,100W/L, the charge-discharge cycle is 82%@20,000 cycles, and the temperature characteristic is more than 80% at –30~65℃.
- The characteristics of the prototype manufactured by applying to the mass production process are 1.5V-25Ah
Ⅳ. Research achievements ∘ 6 patent applications ∘ 1.5V-30Ah hybrid capacitor prototype using mass production process ∘ PRT vehicle demonstration using hybrid capacitor
Ⅴ. Plan to utilize R & D results ∘ Commercialization of hybrid capacitor - Commercialization through technology introduction and prototype explanation to company - Joint development of mass production process technology with technology transfer company
∘ Improvement of hybrid capacitor technology through continuous development and expansion of application field
- Development of high-energy hybrid capacitors for long-distance electric vehicles - Development of high-power hybrid capacitor for ESS (Energy storage system)
