The dwindling sources of fossil fuels and rapidly rising CO2 levels necessitate a much more efficient use of energy. Better energy storage technology is especially needed if renewable sources of energy are to be used widely. Lithium-ion batteries are the most promising answer so far, but more demanding applications such as electrical vehicles or home powering require substantial increase in storage capacity and charge rates. Characterisation of actual and promising novel materials is of critical importance towards this goal, as better understanding of their mechanism will have direct impact on the optimisation and development of such materials for energy storage.I propose to work on one of the most promising material for negative electrodes in lithium-ion batteries, silicon. The goal is to determine the structural changes that occur inside the electrode and to study the reactions arising on the surface. The studies will be performed using a combination of sophisticated solid-state Nuclear Magnetic Resonance (NMR) methods and state-of-the-art periodic DFT calculations. New methods will be developed for ex-situ NMR initially, with the long-term objective of adapting them to the in-situ NMR design in the world-specialist laboratory (host laboratory). The in-situ setup makes it possible to study batteries in real time during charge and discharge by NMR, thereby capturing transient transformations that can be missed by ex-situ studies.Via the proposed research programme, I will bring expertise in new NMR methodologies to the Cambridge laboratory and I will at the same time learn new skills in the area of materials chemistry and battery technology.