The performance and the lifetime of energy storage devices can be hindered by the growth of metal dendrites during operation. Electrolytes having dendrite-inhibiting additives can result in significant improvement. In particular, energy storage devices having an electrode containing a metallic element, M1 can be characterized by a non-aqueous, liquid electrolyte having a first salt and a dendrite-inhibiting salt. The first salt can have a cation of M1 and the dendrite-inhibiting salt can have a cation of metallic element, M2, wherein the cation of M2 has an ionic size greater than, or equal to, the cation of M1.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with Government support under Contract DE-AC0576RL01830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.