杂化电解质竹炭燃料电池阳极熔融碳酸盐作用机制研究

Direct carbon fuel cell is considered to be a very promising power generation technology due to its high energy conversion efficiency, less emission and high fuel utilization. Hybrid electrolyte direct carbon fuel cell is formed by adding molten carbonate into solid oxide fuel cell anode, and its electrochemical performance can be enormously improved. However, how does the molten carbonate work is still unclear..Therefore, research thoughts are put forward as follows: construct a hybrid electrolyte DCFC with a Ni-SDC (Ce0.8Sm0.2O1.9) anode; built the anodic activation polarization mathematic model, combining with electrochemical oxidative behavior of carbon and temperature distribution in the fuel bed; understand the interaction on O2- conduction between SDC phase and molten carbonate phase; built the anodic ohmic polarization computation model; summarize the control mechanism of bamboo charcoal wetting properties according to the experimental studies on bamboo charcoal contact angle regulation and carbonate component majorization; study the actual performance of the composite electrolyte DCFC fed with bamboo charcoal with high wetting property; finally clarify the functional mechanism of molten carbonate in a hybrid electrolyte DCFC based on the contrastive analysis between the experimental results and calculation results. The research could provide the theoretical basis for hybrid electrolyte DCFC anode performance optimization and the reference for the development of the clean and efficient energy conversion technologies. Therefore, the project research has great academic meaning.

直接碳燃料电池（DCFC）具有能量转换效率高、污染物排放少、燃料利用率高等优点，是一种极具发展前景的高效发电技术。固体氧化物DCFC阳极引入熔融碳酸盐后构成杂化电解质DCFC，燃料电池性能大幅提高，但碳酸盐的作用机制尚不明确。为此，本项目拟开展如下研究：基于Ni-SDC(Ce0.8Sm0.2O1.9)阳极构建杂化电解质DCFC，研究碳的电化学氧化方式和燃料层温度分布规律，建立阳极活化极化数学模型；研究O2-传导中SDC相与碳酸盐相的相互作用，建立阳极欧姆极化计算模型；通过竹炭接触角调控、碳酸盐组分优化等实验解析熔融碳酸盐中竹炭润湿特性的控制机制；以改性竹炭为燃料考察DCFC实际性能，与计算结果对比分析阐明杂化电解质DCFC阳极熔融碳酸盐的作用机制。本研究可为杂化电解质DCFC性能优化提供理论基础，为能源高效转化新技术开发提供借鉴，具有重要理论与实践意义。

固体氧化物燃料电池（Solid Oxide Fuel Cell, SOFC）由于具有能量转化效率高、燃料适应性强、余热利用率高、环境友好等优点备受关注。本项目通过合成新型阴极材料和电解质材料、优化电池结构等构建了适合中低温运行的SOFC单电池，并系统研究了电化学反应机理。.探究了A位La、Sr缺陷对LSCF（La0.6Sr0.4Co0.2Fe0.8O3-）电催化活性的影响，确定LSCF中La、Sr的缺陷量为0.05，合成(LS)0.95CF（(La0.6Sr0.4)0.95Co0.2Fe0.8O3-）钙钛矿氧化物，通过表征测试发现：与LSCF相比，阴极系列中(LS)0.95CF具有更多的氧空穴，应用于电池阴极有更强的离子传导能力及氧传输能力；以(LS)0.95CF为阴极制备的对称电池在不同温度下的电极阻抗与LSCF电极的相比大幅降低；阳极支撑型单电池(Ni-SDC||SDC||(LS)0.95CF在650°C的输出功率可达 212mW cm-2，说明La、Sr的缺陷可以提高电极氧还原反应能力。.通过Ce位掺杂金属元素（Ni、Cu、Co、Fe）对SDC电解质进行改性，较低烧结温度下制备金属掺杂SDC电解质，对其相结构、收缩率、电化学阻抗、离子电导率、微观形貌等进行表征，并与原始SDC电解质进行对比分析，结果表明：降低煅烧温度的SDC金属掺杂系列具有钙钛矿基本相结构，电导率有所提升，制备的对称电池电化学性能测试表明，在适当的掺杂含量下，电解质掺杂Ni、Co、Fe等金属可在一定程度上降低电化学阻抗，提高电化学性能。.以较低煅烧温度的金属掺杂SDC为电解质制备了SOFC单电池，探究了SDC电解质中掺杂金属的种类及含量对单电池输出性能的影响，实验结果表明，掺杂不同金属元素或掺杂不同含量时，单电池性能均有差异，但掺杂其中一种金属元素时，在适当的掺杂含量下可提高单电池性能，说明在电解质引入Ni、Cu、Co、Fe等金属元素可以作为提高SOFC性能的优化方法之一。