Corrosion protection of secondary lithium electrodes in organic electrolytes

Hydrocarbons show considerable surface activity in organic electrolytes; they, at least partially, displace the polar organic solvent molecules from any solid/electrolyte interface. Saturated hydrocarbons are chemically stable even versus lithium or lithium-rich alloys, and thus they are able to delay the irreversible reduction of organic electrolytes by these highly active negatives, i.e., they delay corrosion and surface filming of the negatives.

As surface filming of lithium strongly controls the growth of lithium dendrites during electroplating, a delay in the filming process significantly decreases dendrite growth. Prevention of dendrite growth, however, requires speedy protection of freshly created “dynamic’ surfaces and, hence, a high concentration (and solubility) of the hydrocarbon surfactant. On the other hand, for the protection of “static‘ electrodes under open cell conditions, even relatively insoluble surfactants may suffice.