Using Mn-Co containing compounds formed through biological processes as precursors for development of electrode materials for energy storage applicat

目前，商用锂离子电池的正极材料多采用含锰钴氧化物。对Co-Mn-O-H体系的进一步研究正在研究在其他储能应用中有潜力的相，如超级电容器材料或作为钠离子电池的电极材料。开发新的电活性材料包括控制材料的组成、颗粒大小和形貌以优化其电化学性能。通过微生物过程形成的材料将是一种新的制备Mn-Co相的途径。据了解，白纹希瓦氏菌MR-1可以从废弃锂离子电池产生的混合金属渗滤液中沉淀出溶解的Mn2+。形成的沉淀物被确认为MnCO3，一种已知的用于生产锂离子电池电极材料的前光标材料。在大多数情况下，除锰具有很高的选择性，但也观察到了诸如含钴沉淀物的‘杂质’。这些杂质实际上可能有利于该材料的未来使用，并通过对微生物的遗传操作来研究和控制它们的变异。此外，在厌氧条件下，S.onedensis能够通过产生金属纳米颗粒来减少一系列金属离子。这种双重作用表明，该细菌可能被用于生产受氧气可获得性和金属离子浓度等条件影响的混合金属材料。这些研究途径将单独或结合在一起，提供获得微生物合成正极材料的途径。通过微生物过程形成的相将通过一系列技术来表征，包括用于鉴定存在的晶相的X射线粉末衍射，用于研究颗粒尺寸和形貌的扫描电子显微镜，对于储能应用至关重要的颗粒大小和形貌，以及用于研究电活性性质的电化学表征。一旦确定了具有良好电化学性质的材料，就将建立开发用于能源应用的设备的方法，如超级电容器或电池。然后将测试这些设备的长期稳定性。监测作为电位函数的结构变化，即在使用设备时可能发生的任何变化，提供有关材料在使用中的性能的关键信息。随着最近在极端条件科学中心(CSEC)建立了最先进的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池的开发将使这些变化得以研究。拟议的项目将包括材料的生物合成、材料的结构和电化学特性以及原型设备的开发。

Currently, Mn-Co containing oxides are used as cathode materials in commercial lithium ion batteries. Further research into the Co-Mn-O-H system is investigating phases that have potential in other energy storage applications such as supercapacitor materials or as electrode materials in Na-ion batteries. Development of new electroactive materials involves controlling the composition, particle size and morphology to optimise their electrochemical characteristics.Materials formed though microbial processes would be a novel route to produce Mn-Co phases. It is known that Shewanella oneidensis MR-1 can precipitate dissolved Mn2+ from mixed-metal leachates produced from end-of-life lithium ion batteries. The precipitate formed was confirmed as MnCO3, a known pre-cursor material used for production of electrode materials in lithium ion batteries. For the most part, Mn removal is highly selective but 'impurities', such as Co-containing precipitates have been observed. The impurities may in fact be beneficial to the future use of the material and their variation investigated and controlled through genetic manipulation of the microbe. Furthermore, S. oneidensis is able to reduce a range of metal ions with the production of metal nanoparticles under anaerobic conditions. This dual action suggests the possibility that this bacterium could be used for the production of mixed metal materials influenced by conditions such as oxygen availability and metal ion concentrations. Separately, or in combination, these avenues of study will provide access to microbially-synthesised cathode materials.The phases formed though microbial processes will 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 and electrochemical characterisation to investigate the electroactive properties. Once materials with good electrochemical properties have been identified, 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.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.