全被动式直接甲醇燃料电池阳极传质机制及调控策略

The micro passive direct methanol fuel cell (DMFC) is regarded as a potential power source for portable applications due to its high energy density, simplicity, easy fuel-recharging, portable and low pollution. However, there have to achieve pure methanol as fuel and passive operation to reduce the volume of the system and improve the output energy density before its practical applications. Effective mass transfer and concentration control play an important role in a passive DMFC feeding with pure methanol, which are also the main technical bottlenecks. A methanol mass transfer control layer and buffer chamber are designed between the fuel reservoir and anode current collect to achieve pure methanol feeding. In order to promote mass effect, multilevel distributions of pore structure was designed in the anode diffusive layer, and an ordered array nano-wire electrode will be fabricated on the diffusive layer directly to improve the electrochemical reaction activity. To keep an appropriate concentration of methanol at the anodic catalyst layer and effectively suppress methanol crossover, the hydrophilic/hydrophobic properties of the cathode diffusive layer will be changed to make water moving back from cathode to anode.The law of coupled mass transfer of multi-components and electrochemical reaction will be studied to improve the cell's performance and fuel utilization.

以便携式电子产品应用为目标的全被动式微小型直接甲醇燃料电池（DMFC）要满足高比能的应用需求,迫切需要直接使用纯甲醇。而采用纯甲醇进样时阳极甲醇的有效传质及浓度控制是制约电池能量转换效率和稳定运行的主要技术瓶颈。本项目通过在储罐和微米孔集流板之间设计甲醇传质控制层和燃料供给缓冲室，实现纯甲醇进料；通过集流板孔结构和孔隙率、支撑层憎水性、扩散层分级孔结构以及催化层有序阵列结构等调控阳极甲醇传质速率,构筑有利于分子、电子和质子相对独立的连续传输通道，研究传质速率与孔结构的关系，阐明阳极甲醇的传质机制；并通过阴极憎水性调控实现阴极"返水",进而协同实现阳极催化层低浓度甲醇的有效控制、显著抑制甲醇的渗透，阐明电极传质与电化学反应的耦合规律，探索影响电池稳定运行的因素，为实现全被动式微型DMFC高效、稳定运行奠定基础，推进微小型DMFC实用化进程。

以便携式电子产品应用为目标的全被动式微小型直接甲醇燃料电池（DMFC）要满足高比能的应用需求,迫切需要直接使用纯甲醇。而采用纯甲醇进样时阳极甲醇的有效传质及浓度控制是制约电池能量转换效率和稳定运行的主要技术瓶颈。本项目通过在储罐和阳极集流板之间设计甲醇传质控制层和燃料供给缓冲室，实现纯甲醇进料；通过扩散层分级孔结构、催化层有序阵列结构等调控阳极甲醇传质速率,构筑有利于分子、电子和质子相对独立的连续传输通道，研究传质速率与孔结构的关系，阐明阳极甲醇的传质机制；并通过阴极憎水性的调控实现阴极“返水”,进而协同实现阳极催化层低浓度甲醇的有效控制、显著减低甲醇的渗透，深入探索影响电池稳定运行的因素，为实现全被动式微小型DMFC高效、稳定运行奠定基础，推进微小型DMFC实用化进程。