Improving Performance of Li-Ion Battery Anodes with Polymeric Coating
For LIB anodes, there are two important issues to deal with for achieving high-energy and high-power performance. First, decomposition of electrolyte at the anode surface takes place at sufficient low potential leading to the formation of a passivation film, known as solid electrolyte interphase (SEI). Formation of the SEI consumes Li ion inventory and hence reduces the overall capacity of the battery cell. Therefore, the amount of the stable SEI layer should theoretically kept at a minimum. Secondly, the power densities for the state-of-the-art graphite electrodes remain insufficient.
In this presentation, we will report our progress in developing polymeric coatings for LIB anodes, particularly for graphite and graphite/Si composite. It is demonstrated that the properties of the anodes in different aspects, such as chemical/electrochemical, mechanical, and wetting behaviors, can be dramatically changed with the combination of polymer chemistry. In particular, it is shown that both the cycle life (Fig. 1) and even the power performance (Fig. 2) of the anodes can be remarkably enhanced by simple polymer coating.