Dendrite Suppression by a Polymer Coating: A Coarse‐Grained Molecular Study

Abstract

A major hurdle to the successful deployment of high‐energy‐density lithium metal based batteries is dendrite growth during battery cycling, which raises safety and cycle life concerns. Coating the Li metal anode with a soft polymer layer has been previously shown to be effective in suppressing dendrite growth, leading to uniform lithium deposition even at high current densities. A 3D coarse‐grained molecular model to study the mechanism of dendrite suppression is presented. It is found that the most effective coatings delay or even prevent dendrites from penetrating the polymer layer during deposition. The optimal deposition can be achieved by jointly tuning the polymer stiffness and relaxation time. Higher polymer dielectric permittivity and coating thickness are also effective, but the deposition rate and, therefore, the charging current density is reduced. These findings provide the basis for rational design of soft polymer coatings for stable lithium deposition.

Stabilizing metal battery anodes through the design of solid electrolyte interphases

“…70 Recent coarse-grained model and simulation study reported that the relaxation time of the polymeric ASEI is another key factor in determining the stability of the deposition underneath. 71 However, designing an SEI solely based on these parameters is more complicated than apparent. Recent chemomechanical analyses show that high modulus inorganics with minimally reconfigurable ion-conducting domains in fact lead to unstable electroplating due to density-driven rather than pressure-driven instabilities.…”

Polymers in Lithium‐Ion and Lithium Metal Batteries

“…[ 148,149 ] To sum up, ideal PASEIs should meet several critical requirements: 1) high ionic conductivity; 2) outstanding mechanical performance with flexibility and a high modulus to adapt to the deformation of electrodes; 3) forming a uniform, defect‐free, and conformal layer to cover the entire electrode surface; 4) good chemical and electrochemical stability. [ 21,150 ]…”

Issues and solutions toward zinc anode in aqueous zinc‐ion batteries: A mini review

“…Surface coating has been widely used to inhibit the formation of Zn dendrites by homogenizing the electric field distribution on an electrode surface, adjusting the ion transmission flux, and affecting the growth direction of Zn. 55,69 To suppress dendrites, an ideal coating layer should possess certain stability, high ionic conductivity, and good affinity with electrolytes. The reported coatings contain metal-organic frameworks (MOF), 66 carbon matrix, 70 inorganic metal oxides, 49 polymers, 71 and so on.…”