Graphene Quantum Dots as an Electrode Material for Hybrid Battery-Supercapacitors

石墨烯量子点作为混合电池-超级电容器的电极材料

• 批准号: 2867966
• 金额: --
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2867966
• 关键词: Graphene; Quantum; Dots; Electrode; Material

A battery-supercapacitor hybrid (BSH) is a promising type of energy storage device that combines the advantages of both batteries and supercapacitors, allowing them to benefit from high energy density, high power density, long life cycle, fast charging times and high-temperature capabilities1. However, fabricating reliable BSH exhibiting high performance remains very challenging and little studied. This project aims to address this research gap by exploiting the unique properties of graphene quantum dots (GQDs), i.e. to synthesise and embed them in the fabrication of BSH electrodes controllably in a low-cost process. To realise the potential high for performance BSHs, the search for methods to improve their properties further, making them competitive against advanced batteries and conventional supercapacitors, is ongoing. One option is to integrate graphene quantum dots (GQDs, nanometre-sized semiconductor particles with tuneable electronic properties) onto both electrodes of the device. GQDs retain the characteristics of graphene (fast-moving electrons, high thermal conductivity, quantum tunnelling, etc.), but exhibit the quantum confinement effect, resulting in an opening of the material's bandgap, allowing them to behave as a semiconductor, in addition to size and edge effects. Furthermore, GQDs display a strong adsorption capacity for a wide range of electrolyte ions, including lithium, sodium and other ions commonly used in conventional energy storage devices. The incorporation of GQDs into a supercapacitor-type electrode increases the energy density and capacitance potential2, while the advantages to including GQDs on a battery-type electrode include high reversible specific capacity, improved rate capability, and longer life cycle3. BSHs without the addition of GQDs have the potential to maintain a life cycle equal to 4000% versus that of a standard lithium-ion battery1,4. The inclusion of GQDs will result in a further increase of the life cycle since they can regulate the internal structure of the electrodes, preventing damage and therefore reducing the need for their frequent replacement, extensive mineral mining, CO2 emissions during production and environmental issues surrounding the disposal of spent lithium-ion batteries. Despite the high potential of GQDs, to the best of my knowledge, so far, there are no reports on reliable BSHs where GQDs are integrated into both electrodes. Moreover, the role and effect of GQD structure (zigzag and armchair edges, and functionalisation degree) on the properties of the GQDs, and the resulting electrodes and device are not defined yet. Therefore, this project aims to fill this gap and by developing reliable GQD-based electrodes for BSH applications. We aim to: (i) Establish the relationship between the structure and properties of the GQDs and electrodes produced using a systematic characterisation of the GQDs and electrode behaviours; (ii) use molecular dynamic simulations to optimise the experimental design and to predict the response of the device produced; (iii) produce a prototype demonstrator of a hybrid power device based on the most promising simulation and experimental results.

电池-超级电容器混合动力（BSH）是一种很有前景的储能装置，它结合了电池和超级电容器的优点，使其具有高能量密度、高功率密度、长寿命周期、快速充电时间和耐高温等优点。能力1。然而，制造具有高性能的可靠 BSH 仍然非常具有挑战性，而且研究很少。该项目旨在通过利用石墨烯量子点（GQD）的独特性质来弥补这一研究空白，即以低成本工艺可控地将其合成并嵌入到 BSH 电极的制造中。为了实现 BSH 的高性能潜力，我们正在寻找进一步提高其性能的方法，使其与先进电池和传统超级电容器相比具有竞争力。一种选择是将石墨​​烯量子点（GQD，具有可调电子特性的纳米尺寸半导体颗粒）集成到设备的两个电极上。 GQD保留了石墨烯的特性（快速移动的电子、高导热性、量子隧道效应等），但表现出量子限制效应，导致材料的带隙打开，使它们能够表现出半导体的特性，此外尺寸和边缘效应。此外，GQD 对多种电解质离子表现出强大的吸附能力，包括锂、钠和传统储能装置中常用的其他离子。将GQD纳入超级电容器型电极可提高能量密度和电容潜力2，而将GQD纳入电池型电极的优点包括高可逆比容量、提高的倍率性能和更长的生命周期3。与标准锂离子电池相比，不添加 GQD 的 BSH 有可能保持相当于 4000% 的生命周期1,4。 GQD 的加入将进一步延长生命周期，因为它们可以调节电极的内部结构，防止损坏，从而减少频繁更换的需要、广泛的矿物开采、生产过程中的二氧化碳排放以及围绕电极的环境问题。废旧锂离子电池的处置。尽管 GQD 潜力巨大，但据我所知，到目前为止，还没有关于将 GQD 集成到两个电极中的可靠 BSH 的报道。此外，GQD 结构（锯齿形和扶手椅边缘以及功能化程度）对 GQD 性能以及所得电极和器件的作用和影响尚未确定。因此，该项目旨在填补这一空白，并为 BSH 应用开发可靠的基于 GQD 的电极。我们的目标是： (i) 通过对 GQD 和电极行为进行系统表征，建立 GQD 和电极的结构和性能之间的关系； (ii) 使用分子动力学模拟来优化实验设计并预测所生产装置的响应； (iii) 基于最有希望的模拟和实验结果生产混合功率器件的原型演示器。