Solid-State Chemistries Stable with High-Energy Cathodes for Lithium-Ion Batteries

In
the pursuit of higher-energy-density lithium-ion batteries,
one major challenge is the stability of high-capacity or high-voltage
cathodes with electrolytes. An understanding of how different chemistries
interact with high-energy cathodes is required to enable the rational
design of coatings or solid electrolyte materials that offer long-term
stability with the cathode. Here, we systematically evaluated the
thermodynamic stability among a broad range of solid-state chemistries
with common cathodes. Our thermodynamic analyses confirmed that the
strong reactivity of lithiated and delithiated cathodes greatly limits
the possible choice of materials that are stable with the cathode
under voltage cycling. Our computation reaffirmed previously demonstrated
coating and solid electrolyte chemistries and suggested several new
stable chemistries. In particular, the lithium phosphates and lithium
ternary fluorides, which have high oxidation limits, are promising
solid-state chemistries stable with high-voltage cathodes. Our study
provides guiding principles for selecting materials with long-term
stability with high-energy cathodes for next-generation lithium-ion
batteries.