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Advanced zinc air battery based on novel bifunctional electrocatalysts and ion-selective conduction membrane

Title
Advanced zinc air battery based on novel bifunctional electrocatalysts and ion-selective conduction membrane
Other Titles
차세대 아연 공기전지를 위한 고성능의 양기능성 촉매 및 이온 선택 전도 멤브레인에 관한 연구
Author
Lin chao
Advisor(s)
Jung-Ho Lee
Issue Date
2020-02
Publisher
한양대학교
Degree
Doctor
Abstract
Sustainable, clean energy sources from sunlight, geothermal, wind, heat have been used to replace highly pollution fossil fuels gradually to satisfied the energy requirement of the development of modern society. Due to the intermittent distribution of sustainable energy sources in space and time, strenuous efforts have been dedicated to developing advanced technologies for clean energy harvesting. Among the energy conversion and storage technologies, metal (i.e. Li, Na, K, Al, Mg, Fe, Zn) air batteries have been made significant progress since their remarkable theoretical energy densities. Especially, the Zn air batteries (ZABs) with high specific energy density of 1353 W h kg-1, low expected cost of 10 $ kW-1 h-1, extremely high safety and reliability, are highly promising as the next-generation energy storage technology. However, the low operating voltage (normally 1~1.3 V) and poor cycling stability, which strongly affect by the catalytic performance and reliability of air electrode, still obstruct the commercialization of rechargeable ZABs. Therefore, exploration of promising bifunctional air electrode with efficient reaction kinetics of oxygen reduction/evolution reactions and robust reversibility for ZABs are highly desired. Otherwise, with the great interest in wearable, solid-state rechargeable ZABs, the development of flexible solid-state electrolytes is also achieved widespread attention. Taking the above considerations, we rational design of cobalt based electrocatalysts on the bifunctional application in ZABs, with regulated Co components featuring from nanoparticles to sub-nanoclusters and single atom configuration. The as-designed air electrodes possess enhanced bifunctional electrocatalytic activity and robust long-term stability for ZABs. Furthermore, two different kinds of flexible solid-state electrolytes were successfully prepared for alkaline ZABs and acidic ZABs, respectively. Both of the flexible solid-state alkaline ZABs and asymmetric-electrolyte aqueous acidic ZABs exhibit excellent cycling efficiency (> 70 %). 1. Reasonable construction of metal-metal oxide interfaces in multiphase nanocomposites is an effective approach to achieving advanced bifunctional electrocatalysts for both of OER and ORR. Here, electrocatalysts based on various kinds of Co nanocomposites (Co, Co/Co3O4, and Co3O4) anchored on three-dimensional nitrogen doped carbon nano-framework (3D-NC) are developed by simple pyrolysis approach. Originating from the optimal electron/mass transfer environment providing by the interpenetration of metallic Co and Co3O4 and tightly encapsulated nitrogen doped graphitic carbon shells, the partially oxidized Co/Co3O4/3D-NC bifunctional electrocatalysts outperform superior ORR and OER activity compared with Co/3D-NC and Co3O4/3D-NC. Impressively, the Co/Co3O4/3D-NC based solid-state rechargeable Zn air batteries exhibited high open-circuit voltage, record round-trip efficiency of 75% and highly flexibility, holding great potential for wide range of wearable and portable electronic devices application. 2. A flexible Zn ion selective transport membrane (ZnSTM) has been demonstrated as a separator for new type of asymmetric-electrolyte aqueous ZABs with acidic catholyte and alkaline anolyte. The hydrophobic ZnSTM effectively prevent the neutralization reaction between hydrated proton and hydroxide, and selectively transfer the metal ion (e.g. Zn2+) for charge balance between anolyte and catholyte based on its numerous N species. Moreover, a simple synthesis strategy for the ultrafine Co subnanoclusters anchored 2D nitrogen doped carbon nanosheets is proposed (Co/2D-NSs). The strong metal support interaction (SMSI) enables the Co/2D-NSs to have uniform sub-nano cobalt clusters, robust ORR and OER activities in acidic electrolytes. Coupling the Co sub-nanocluster related acidic air cathode with Zn metal anode, the ZnSTM based asymmetric-electrolyte aqueous ZABs demonstrated high open-circuit voltage (OCV) of 2.1 V and operating voltage (e.g. 1.55 V @ 10 mA cm-2 for ZABs), great specific energy density of 1354 Wh/kgZn and robust charge-discharge durability with nice cycling efficiency (70.8% after 300 cycles in 100 h for ZABs). This novel strategy for synthesis of multivalent metal ion semi-permeable conductive membrane open up a new concept to preparation solid-state separator for asymmetric-electrolyte energy storage systems with a variety of cathodes and anodes and provide the possibility to develop next-generation solid-state flexible asymmetric-electrolyte energy storage devices. 3. Although single metal atom-based catalysts can maximize the usage of metal atoms as active sites, selection satisfactory supports possess strongly interact with isolated atoms and prevent the aggregation of metal atoms still a critical challenge. Here, we design a facile wet-chemistry strategy to controllable construct a metal-incorporated polymer which consist of high density, single-atom Co and nitrogenated coordination polymer (Co@C2N). Aberration-corrected scanning transmission electron microscopy (AC-STEM), X-ray absorption spectroscopy (XAS) analysis results confirm the densely isolated atomic structure of Co. Importantly, ultra-stable durability with a lifetime of 6000 cycles (1000 h) is achieved by Zn-air batteries with Co@C2N-3 as the rechargeable air electrode. Normally, the bifunctional active sites always be poisoned by the accumulation of surface oxides (Co=O) during charge process. Based on the ex-situ HR-TEM results after long-term stability test, the excellent cycling stability can be attributed to the recombination of Co active species to form reversible CoOOH phase. |현대 사회의 발전에 따라, 요구되는 에너지량을 만족하기 위해 개발되었던 석유 에너지를 점진적으로 대체하기 위해 태양광, 지열, 풍력 등과 같은 지속 가능한 청정 에너지 원이 개발되었다. 그러나, 이러한 에너지원은 공간과 시간에 크게 의존하는 한계 때문에, 청정 에너지를 효율적으로 저장할 수 있는 첨단 기술 개발이 요구되었다. 현재 에너지 변환 및 저장 기술들 중, 금속 (Li, Na, K, Al, Mg, Zn, Fe) 공기 전지는 높은 이론적 에너지 밀도를 갖기 때문에 많은 연구 개발이 진행되고 있다. 특히 아연 공기전지(Zinc air battery, ZABs)는 1350Whkg-1의 높은 에너지 밀도, 10$kW-1h-1의 낮은 단가, 고안정성 및 신뢰성으로 차세대 에너지 저장 기술로 매우 유망하다. 하지만 낮은 구동 전압 (일반적으로 1~1.3V)과 열악한 사이클링 안정성은 ZABs의 상용화에 있어 큰 걸림돌이다. 따라서, 산소 환원/산화 반응에 대한 효율적인 반응 동역학 및 가역성을 갖는 양기능성 공기전지 디자인 개발이 강력하게 요구된다. 한편, 유연하며, 재충전이 가능한 고성능의 ZABs에 대한 큰 관심에 따라, 유연한 고체 전해질의 개발 또한 크게 주목을 받고 있다. 위의 사항을 고려하여, 우리는 코발트 성분 기반의 나노 입자, 서브 나노클러스터, 단일 원자 구성을 갖는 양기능성 전기 촉매들을 개발했다. 설계된 전기 촉매는 ZABs에서 향상된 안정성과 높은 양기능성 촉매 특성을 보유하였다. 또한, 두 가지의 다른 유연한 고체전해질은 산성 ZABs와 염기성 ZABs을 위해 각기 성공적으로 제조되었으며, 둘 모두 우수한 사이클링 효율을 나타내었다. 1. 다상의 나노 복합체에서 금속-금속 산화물의 계면 구조는 OER과 ORR 반응 둘 모두를 위한 양기능성 전기 촉매를 달성하는 효과적인 접근법이다. 여기서, 3차원 질소 도핑 된 탄소 나노 프레임 워크(3D-NC) 위에 다양한 Co 나노 복합체 (Co, Co/Co3O4, Co3O4)를 기반으로 하는 전기 촉매는 간단한 pyrolysis법을 통해 개발되었다. 금속성의 Co와 Co3O4의 혼합체 및 이를 감싸는 질소 도핑 된 흑연 탄소 쉘로 제공되는 최적의 전자/질량 전달 조건은 부분적으로 산화 된 Co/Co3O4/3D-NC 양기능성 전기촉매로써 Co/3D-NC와 Co3O4/3D-NC의 ORR, OER 성능을 능가한다. Co/Co3O4/3D-NC 기반의 아연공기 2차전지는 높은 개방전압, 75%의 효율 및 유연성으로 광범위한 웨어러블 및 휴대용 전자 장치 응용 분야에 대한 큰 잠재력을 가진다. 2. 유연한 Zn 이온 전도성 멤브레인 (ZnSTM)은 ZABs 각 전극단에 사용되는 산성/염기성 전해질에 대한 비대칭성을 갖는 분리막으로써 입증되었다 (AZABs). 높은 소수성을 갖는 ZnSTM은 효과적으로 수소와 수산화 이온의 중성화 반응을 방지하며, 또한 멤브레인 내 질소 종은 전해질 간 전하 균형을 위해 선택적으로 Zn 이온을 전달한다. 게다가, 2D 질소 도핑 된 탄소 나노시트와 강하게 상호작용하는 Co 클러스터 (Co/2D-NSs)를 위한 새로운 합성 방법이 제시되었다. 금속/서포트 간 강한 상호작용(SMSI)은 Co/2D-NSs가 균일한 서브 나노 스케일의 코발트 클러스터를 갖게 하며, 산성 전해질에서 안정적인 ORR, OER 성능을 갖게 한다. 이와 Zn 금속 전극을 결합함으로써, ZnSTM 기반의 비대칭성 전해질을 갖는 ZABs는 2.1V의 높은 개방전압, 높은 에너지 밀도 (1354Wh/kgZn), 높은 충방전 내구성 및 효율을 보였다 (300cyc 이후 70.8%, 100시간 기준). Zn 이온 반투과성 전도성 막 합성을 위해 제시 된 전략은 양/음극으로 구성되는 비대칭 전해질 에너지 저장 시스템에서 고체 분리기에 대한 새로운 개념을 열고, 차세대 에너지 저장 장치 개발에 대한 가능성을 제공한다. 3. 우리는 고밀도의 단일 원자 Co와 질소화 된 배위중합체(Co@C2N)로 구성 되는 금속-고분자 중합체를 제작하는 간단한 습식 화학 전략을 설계하였다. Aberration-corrected scanning transmission electron microscopy (AC-STEM), X-ray absorption spectroscopy (XAS) 분석 결과는 고밀도의 고립된 원자구조를 갖는 Co를 확인하였다. ZABs에서 Co@C2N-3를 충전식 전극으로 사용함으로써, 6000cyc (1000h)의 매우 높은 내구성을 달성하였다. 일반적으로, 양기능성 촉매 성능은 충전 중 표면 산화물 (Co=O)의 축적에 의해 열화된다. HR-TEM 결과에 근거하여, 우수한 안정성은 비가역적인 Co=O 결합보다는 가역적인 CoOOH 상을 형성하기 위한 Co 활성종의 재결합에 기인한다.; Sustainable, clean energy sources from sunlight, geothermal, wind, heat have been used to replace highly pollution fossil fuels gradually to satisfied the energy requirement of the development of modern society. Due to the intermittent distribution of sustainable energy sources in space and time, strenuous efforts have been dedicated to developing advanced technologies for clean energy harvesting. Among the energy conversion and storage technologies, metal (i.e. Li, Na, K, Al, Mg, Fe, Zn) air batteries have been made significant progress since their remarkable theoretical energy densities. Especially, the Zn air batteries (ZABs) with high specific energy density of 1353 W h kg-1, low expected cost of 10 $ kW-1 h-1, extremely high safety and reliability, are highly promising as the next-generation energy storage technology. However, the low operating voltage (normally 1~1.3 V) and poor cycling stability, which strongly affect by the catalytic performance and reliability of air electrode, still obstruct the commercialization of rechargeable ZABs. Therefore, exploration of promising bifunctional air electrode with efficient reaction kinetics of oxygen reduction/evolution reactions and robust reversibility for ZABs are highly desired. Otherwise, with the great interest in wearable, solid-state rechargeable ZABs, the development of flexible solid-state electrolytes is also achieved widespread attention. Taking the above considerations, we rational design of cobalt based electrocatalysts on the bifunctional application in ZABs, with regulated Co components featuring from nanoparticles to sub-nanoclusters and single atom configuration. The as-designed air electrodes possess enhanced bifunctional electrocatalytic activity and robust long-term stability for ZABs. Furthermore, two different kinds of flexible solid-state electrolytes were successfully prepared for alkaline ZABs and acidic ZABs, respectively. Both of the flexible solid-state alkaline ZABs and asymmetric-electrolyte aqueous acidic ZABs exhibit excellent cycling efficiency (> 70 %). 1. Reasonable construction of metal-metal oxide interfaces in multiphase nanocomposites is an effective approach to achieving advanced bifunctional electrocatalysts for both of OER and ORR. Here, electrocatalysts based on various kinds of Co nanocomposites (Co, Co/Co3O4, and Co3O4) anchored on three-dimensional nitrogen doped carbon nano-framework (3D-NC) are developed by simple pyrolysis approach. Originating from the optimal electron/mass transfer environment providing by the interpenetration of metallic Co and Co3O4 and tightly encapsulated nitrogen doped graphitic carbon shells, the partially oxidized Co/Co3O4/3D-NC bifunctional electrocatalysts outperform superior ORR and OER activity compared with Co/3D-NC and Co3O4/3D-NC. Impressively, the Co/Co3O4/3D-NC based solid-state rechargeable Zn air batteries exhibited high open-circuit voltage, record round-trip efficiency of 75% and highly flexibility, holding great potential for wide range of wearable and portable electronic devices application. 2. A flexible Zn ion selective transport membrane (ZnSTM) has been demonstrated as a separator for new type of asymmetric-electrolyte aqueous ZABs with acidic catholyte and alkaline anolyte. The hydrophobic ZnSTM effectively prevent the neutralization reaction between hydrated proton and hydroxide, and selectively transfer the metal ion (e.g. Zn2+) for charge balance between anolyte and catholyte based on its numerous N species. Moreover, a simple synthesis strategy for the ultrafine Co subnanoclusters anchored 2D nitrogen doped carbon nanosheets is proposed (Co/2D-NSs). The strong metal support interaction (SMSI) enables the Co/2D-NSs to have uniform sub-nano cobalt clusters, robust ORR and OER activities in acidic electrolytes. Coupling the Co sub-nanocluster related acidic air cathode with Zn metal anode, the ZnSTM based asymmetric-electrolyte aqueous ZABs demonstrated high open-circuit voltage (OCV) of 2.1 V and operating voltage (e.g. 1.55 V @ 10 mA cm-2 for ZABs), great specific energy density of 1354 Wh/kgZn and robust charge-discharge durability with nice cycling efficiency (70.8% after 300 cycles in 100 h for ZABs). This novel strategy for synthesis of multivalent metal ion semi-permeable conductive membrane open up a new concept to preparation solid-state separator for asymmetric-electrolyte energy storage systems with a variety of cathodes and anodes and provide the possibility to develop next-generation solid-state flexible asymmetric-electrolyte energy storage devices. 3. Although single metal atom-based catalysts can maximize the usage of metal atoms as active sites, selection satisfactory supports possess strongly interact with isolated atoms and prevent the aggregation of metal atoms still a critical challenge. Here, we design a facile wet-chemistry strategy to controllable construct a metal-incorporated polymer which consist of high density, single-atom Co and nitrogenated coordination polymer (Co@C2N). Aberration-corrected scanning transmission electron microscopy (AC-STEM), X-ray absorption spectroscopy (XAS) analysis results confirm the densely isolated atomic structure of Co. Importantly, ultra-stable durability with a lifetime of 6000 cycles (1000 h) is achieved by Zn-air batteries with Co@C2N-3 as the rechargeable air electrode. Normally, the bifunctional active sites always be poisoned by the accumulation of surface oxides (Co=O) during charge process. Based on the ex-situ HR-TEM results after long-term stability test, the excellent cycling stability can be attributed to the recombination of Co active species to form reversible CoOOH phase.
URI
https://repository.hanyang.ac.kr/handle/20.500.11754/123048http://hanyang.dcollection.net/common/orgView/200000436690
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GRADUATE SCHOOL[S](대학원) > MATERIALS SCIENCE AND CHEMICAL ENGINEERING(재료화학공학과) > Theses(Ph.D.)
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