Influence on contouring the lithium metal/solid electrolyte interface on the critical current for dendrites
Contouring or structuring of the lithium/ceramic electrolyte interface, and therefore increasing its surface area, has been considered as a possible strategy to increase the charging current in sold-state batteries without lithium dendrite formation and short-circuit.
In this paper*, published by Energy & Environmental Science, a team of researchers from the Bruce Group in this department, Engineering and Chemistry at Oxford, the Future Battery Research Centre (Shanghai), University of Birmingham and the James Watt School of Engineering (Glasgow) explain the limitations with the contouring techniques.
By coupling together lithium deposition kinetics and the mechanics of lithium creep within calculations of the current distribution at the interface, and leveraging a model for lithium dendrite growth, they show that efforts to avoid dendrites on charging by increasing the interfacial surface area come with significant limitations associated with the topography of rough surfaces.
These limitations are sufficiently severe such that it is very unlikely that contouring could increase charging currents while avoiding dendrites and short-circuiting to the levels required. By way of example, they illustrate how a sinusoidal topography raises the charging current before dendrites occur by approximately 50% over a flat interface.
