2024英国莱斯特大学–中国留基委联合博士奖学金申请
奖学金:莱斯特大学博士四年学费和生活费全包;每年另加£5,000实验费用。
申请截至日期以及其他重要信息:12月20号,2023:
https://le.ac.uk/study/research-degrees/funded-opportunities/china-scholarship-council
Note: 对此项目感兴趣的同学请先在微信/邮件联系项目负责人,莱斯特大学杨博(第二页)
入学日期: 2024年10月
学历要求:
- 本科211学历及以上,绩点3.5以上;硕士科研领域包括物理化学, 电化学或材料分析
- 雅思(学术类)6.0分、托福80分
申请要求资料:
- CV
- ‘个人陈述’(解释你为什么想在莱斯特攻读博士学位)
- 研究计划(可直接使用提供的research proposal,见第三页)
- 学位和学历证书
- 两封推荐书(‘副高级以上专家或教授)
项目提案(英文版请看第三页):电位循环下枝晶锂原位形成过程的 3D X 射线表征:实验与理论
超高储能方式在清洁能源和可持续发展中发挥着不可或缺的作用。锂金属负极是锂基电池的未来,因为负极材料具有巨大的理论容量(3860 mAh g-1),比钴酸锂电池中使用的传统石墨负极(372 mAh g-1)高出10倍。可是为什么锂金属电池还没在社会推广呢?其中最大的挑战与锂枝晶的形成有关[1, 2]。在电池循环过程中,锂离子在阳极和阴极之间不断穿梭。经过几次循环后,文献中广泛报道的锂枝晶的形成会降低电池的库仑效率。此外,如果电池连续循环,枝晶最终会生长到直接“桥接”电池两极,从而导致短路,在某些情况下甚至导致电池爆炸。可视化此微观过程将很有可能是解决这一问题的关键,从而才能够战略性地改善电池循环过程中相互影响的成核动力学和锂离子的传质。
在此博士生项目的第一年,我们将开发操作电化学和非侵入性成像技术(光学和 3D-X 射线断层扫描),以直接实时观测电池循环过程中锂枝晶的形成和溶解。预计在第二年年底,这位博士生致力于将枝晶的形成速率与协同的数值模拟相结合,以回答:对商用电解质中锂离子的传质极限动力学的调控是否可以影响枝晶的形成动力学?[3] 从数值模型中获取的见解或将使此博士生在最后两年开发出枝晶减缓的策略(电解质粘度、锂离子浓度、电极形状等参数)。
成功申请到此项目的博士生将获得莱斯特大学化学学院(Dr Yang,第一导师; 牛津大学本硕博毕业)和工程学院(Prof Bo Chen,第二导师)的无条件支持。杨博士是工况条件下光电化学分析测量技术方面的专家,并在有限差分模拟方面拥有丰富的专业知识;有限差分模拟可以从建模的角度补充对循环过程中锂离子传质方面的物理见解。杨博士也在可持续材料加工中心任职,该研究中心可提供一套电化学和表面表征设备,包括但不限于恒电位仪、手套箱(用于电池合成)、3D 光学轮廓仪和原子力显微镜。陈教授是 EPSRC 早期职业研究员 (EP/R043973/1),他在苛刻环境下的材料性能领域一直获得广泛的国际认可。作为一位富有热情的学者,他曾指导并成功完成了 8 名博士学位。他 20% 的研究成果位于前 10% 的引用百分位数,并且 58% 的成果有国际共同作者。我们很高兴能够及时启动这个博士项目,因为您将成为英国首波关联显微技术的早期开发使用者,因为这套仪器是授予我们大学的 EPSRC 战略设备 (EP/X014614/1),可以以 3D 方式实时重建电池周期中锂枝晶的形成过程,空间分辨率低至亚微米级。您将与高级实验官员合作,充分释放这一最先进研究设施的力量,对电池循环过程中锂枝晶的形成进行多尺度和多模态表征。
与当前最先进的锂离子电池相比,稳定、无枝晶的锂金属电池的储能容量可达到其十倍。这个研究方式自下而上的博士项目将极有可能为锂枝晶的形成机制,以及如何通过补充数值模型,减轻这种灾难性的电池故障,提供重要见解。如果最终成功,您将成为彻底改变我们社会的多学科交叉团队中的一员,为与清洁能源和可持续发展相关的全球挑战提供解决方案。
有兴趣申请以上CSC奖学金的同学请联系项目负责人莱斯特大学杨博士:
Jake Yang
Lecturer of Physical Chemistry
Centre for Sustainable Materials Processing,
School of Chemistry,
University of Leicester, University Road, Leicester,
LE1 7RH, UK
WeChat ID: Chemist037
Departmental profile: https://le.ac.uk/people/jake-yang
telephone: +44 (0)116 252 2140
email: my216@leicester.ac.uk
Project proposal: 3D X-ray Characterisation of in situ Lithium Dendrite Formation during Potential Cycling: Experiment and Theory
Ultra-high energy storage solution plays an integral part in Clean Energy and Sustainability. Lithium metal anodes are the future of lithium-based batteries owing to the colossal theoretical capacity of the anode material (3860 mAh g-1), which is 10 times higher than the conventional graphite anode used in lithium-cobalt-oxide batteries (372 mAh g-1). But why are we not using lithium metal anode-based batteries? The biggest challenge is associated with the undesired formation of lithium dendrites.[1, 2] During battery cycling, lithium ions are shuttled continuously between the anode and cathode. After a few cycles, the formation of lithium dendrite, which is widely reported in the literature, reduces the battery current efficiency. Moreover, if the battery were to be cycled continuously the dendrite would eventually grow to ‘bridge’ the two battery terminals causing a short-circuit and, in some cases, an explosion. The key to resolving this is being able to visualise, and thus allowing one to strategically change, the intertwined nucleation kinetics and mass-transport of lithium ions during battery cycling processes.
In the first year of this studentship, we will develop operando electrochemical and non-invasive imaging techniques (optical and 3D-Xray tomography) to directly visualise, in real-time, the formation and dissolution of lithium dendrites during battery cycle processes. The rate of the formation of dendrites will be coupled with synergistic numerical simulation towards the end of the second year to answer: how might a switch of the mass-transport limitation of lithium-ions, traditionally seen in state-of-the-art electrolytes, affect the dendrite formation kinetics?[3] Insights from numerical modelling allow dendrite mitigation strategies (electrolyte viscosity, lithium-ion concentration, electrode geometry etc) to be developed in the final year of this PhD.
The successful PhD candidate will receive unconditional support from the School of Chemistry (Dr Jake Yang; primary supervisor) and Engineering (Prof Bo Chen; second supervisor) at the University of Leicester. Dr Yang is an expert in operando opto-electrochemical techniques and has expertise in finite difference simulations; the latter provides complementary insight into the mass-transport of lithium ions during cycling from a modelling perspective. Dr Yang is based in the Centre of Sustainable Material Processing offering a suite of electrochemical and surface characterisation equipment including, but not limited to, potentiostats, glovebox (for battery synthesis), 3D optical profilometer and atomic force microscope. Prof. Chen, an EPSRC Early-career Fellow (EP/R043973/1), is internationally recognised in the area of materials performance at demanding environments. As a passionate academic, he has supervised to successful completion of 8 PhDs. 20% of his research outputs are in top 10% citation percentiles and 58% of his outputs have international co-authorship. We are excited to launch this timely PhD project as you will be the early adopter of the UK’s first-of-its-kind correlative microscopy, EPSRC strategic equipment awarded to our university (EP/X014614/1), allowing the formation of lithium dendrites in battery cycles to be reconstructed in real-time in 3D with spatial resolutions down to sub-micrometre. You will work with a Senior Experimental Officer to fully unlock the power of this state-of-the-art research facility to allow for the multi-scale and multi-modal characterisation of the formation of lithium dendrites during battery cycling.
A stable, dendrite-free Li-metal-based battery offers approximately ten times the energy storage capacity as compared to the current state-of-the-art lithium ion battery. This bottom-up PhD project provides key insights to the formation mechanism of lithium dendrites and how this catastrophic battery failure can be mitigated with complementary numerical modelling. If successful, you will be a part of a multidisciplinary team that revolutionises our society, providing a solution to global challenges associated with Clean Energy and Sustainability.
Key References
- Wood, K.N., et al., Dendrites and pits: Untangling the complex behavior of lithium metal anodes through operando video microscopy.ACS central science, 2016. 2(11): p. 790-801.
- Sanchez, A.J., et al., Plan-view operando video microscopy of Li metal anodes: identifying the coupled relationships among nucleation, morphology, and reversibility.ACS Energy Letters, 2020. 5(3): p. 994-1004.
- Chen, Y., et al., Lithium dendrites inhibition via diffusion enhancement.Advanced Energy Materials, 2019. 9(17): p. 1900019.