Phase field simulation and mechanism study of lithium dendrite suppression by adjusting applied overpotential

Abstract

<p>Li-metal has been considered as the ultralimit anode for lithium-ion batteries due to its high theoretical capacity. However, the growth of lithium dendrites poses a serious threat to the battery life and safety. Suppression of the lithium dendrites is urgent. There are dendrite suppression methods, which either require changing the battery structure or adding additional devices. To succeed in a simple and feasible way, here we show that the suppression of dendrites and the re-flatting of the electrode surface are realized by just adjusting the applied overpotential. In addition, the loss of charging capacity of the battery is negligible, which also ensures the charging efficiency of the battery. The dendrites exhibit anomalous dissolving at the top while still growing at the bottom. We explain the “re-flattening” phenomenon qualitatively physically and quantitatively using the “uphill diffusion” theory. We believe that the pattern of the applied overpotential can be further optimized to achieve a charging process that balances safety and efficiency.<br></p>