RENEWABLE RESOURCES AND CLEAN GROWTH - Developing electroactive materials formed through biological processes for energy storage applications

目前，人们正在研究含镍氧化物、氢氧化物和硫化物作为储能超级电容器材料的可能性。所涉及的合成过程通常涉及高温和/或有毒化学品（例如H2S）。这些材料的开发涉及控制组成，粒度和形态，以优化其电化学特性。通过生物过程形成的材料将是产生含Ni相的新途径，如Ni(OH)2, NixSy。合成生物学工具和技术将被用于设计纳米粒子合成细菌，以优化粒子的使用。提议的项目将涵盖材料的生物合成，材料的结构和电化学特性以及原型设备的开发。已知厌氧细菌Desulfovibrio alaskensis G20能从含镍溶液中产生NixSy纳米颗粒，并能以这种方式从锂离子电池的渗滤液中回收Ni。蛋白质组学数据已经表明，一些基因可以改变大小、组成和形态。专门为alaskensis开发的合成生物学工具将用于测试这些基因改变的影响。有益的突变将被结合起来，以确保所生产的纳米颗粒具有最佳的电化学存储特性，而产生纳米颗粒的细菌也适合该过程。所产生的相将通过一系列技术进行表征，包括x射线粉末衍射来识别存在的晶体相，扫描电子显微镜来研究颗粒大小和形态，这对储能应用至关重要，热分析来研究高温稳定性，电化学表征来研究电活性。一旦建立了具有良好电化学性能的材料，就会建立开发能源应用设备的方法，例如超级电容器或电池。然后将对这些设备的长期稳定性进行测试。监测结构变化作为电位的函数，即在使用设备时可能发生的任何变化，可以提供在使用过程中材料性能的关键信息。随着最近在极端条件下科学中心（CSEC）建立的最新的最先进的x射线粉末衍射设备，可以与x射线粉末衍射仪耦合的电化学电池的开发将允许研究这些变化。

Currently, Ni containing oxides, hydroxides and sulfides are being investigated as possible supercapacitor materials for energy storage applications. The synthetic processes involved often involve high temperatures and/or toxic chemicals (e.g. H2S). Development of these materials involves controlling the composition, particle size and morphology to optimise their electrochemical characteristics. Materials formed though biological processes would be a novel route to produce Ni containing phases, such as Ni(OH)2, NixSy. Synthetic biology tools and techniques will be employed in order to engineer nanoparticle-synthesising bacteria in order to optimise the particles for use. The project proposed will cover both the biological synthesis of the material, the structural and electrochemical characterisation of the materials and development of prototype devices.The anaerobic bacterium Desulfovibrio alaskensis G20 is known to produce NixSy nanoparticles from a nickel containing solution1 and can recover Ni in this way from lithium ion battery leachates2. Proteomics data has already suggested a number of genes that could be targeted to alter size, composition and morphology. Synthetic biology tools developed specifically for use with D. alaskensis will be employed to test the impact of alterations to these genes. Beneficial mutations will be combined to ensure that the nanoparticles being produced are optimised for their electrochemical storage properties and the bacteria producing them are optimised for the process. The phases that are produced would be characterised by a range of techniques including X-ray Powder Diffraction to identify the crystalline phases present, Scanning Electron Microscopy to investigate particle size and morphology, crucial for energy storage applications, thermal analysis to study high temperature stabilities and electrochemical characterisation to investigate the electroactive properties. Once materials with good electrochemical properties have been established, methods to develop devices for energy applications, such as supercapacitors or batteries will be established. These devices will then be tested for their long term stability.Monitoring structural changes as a function of potential, i.e. any changes that may occur on using the device, gives key information on the performance of the material whilst in-service. With the new state-of-the-art X-ray Powder Diffraction Facility recently established in the Centre for Science at Extreme Conditions (CSEC), development of electrochemical cells that can couple with the X-ray Powder diffractometer will allow these changes to be investigated.