Encapsulating Si particles with self-healing organic coatings for the next generation anodes of lithium-ion batteries

Research question

Silicon (Si) is currently becoming a game changer for Li-ion batteries, providing considerably higher energy density than the conventional graphite anodes. However, the complex nature of Si when it alloys with Li renders it very difficult to stabilize: both bulk and surface side-reactions contributes to shorter cycle life. Therefore, Si is limited to rather modest mass loadings in the batteries, and the large part of the battery anode still consists primarily of graphite. In this project, the Ångström Advanced Battery Centre at Uppsala University together with the Li-ion battery producer NoVo Energy, together explore the possibility of stabilizing Si by encapsulating the particles in mechanically flexible organic coatings that can adjust to the large volume changes of Si when it reacts with Li. Moreover, these coatings will provide good ionic conductivity, while also rendering electrodes with high electronic conductivity. The research stretches from materials development to Li-ion battery cell chemistry. If successful, this will open the door for using Si-based materials produced in a more sustainable way than today.

Sustainability aspects

Electrification of the transport sector will have an enormous effect on the greenhouse gas emissions, rendering petrol and diesel history for large segments of the vehicle fleet. For a rapid transition to green energy transport solutions, more highly performing batteries are needed. This will also make it possible to electrify more demanding transport solutions, e.g. heavy-duty vehicles and marine applications. Moreover, it is of interest to replace the materials with high carbon footprint, e.g. graphite. The research thereby has strong impacts on several UN sustainability goals, regarding affordable and clean energy, sustainable cities and responsible consumption and production.