<p>Redox flow
batteries, a promising grid-scale energy storage solution, have an open
architecture that can facilitate a broad range of redox electrolytes. Vanadium
is the most mature chemistry, which is largely due to its symmetry, where all active species are based on
a single parent compound, that allows for inexpensive crossover remediation
via rebalancing; however, the industry has increasingly sought chemistries with
lower-cost and higher-abundance redox couples. Most chemistries cannot be
configured symmetrically, though, necessitating research into capacity-recovery
methods for asymmetric chemistries. In this work, we adapt our previously
developed levelized cost of storage model, which tracks capacity fade and
recovery and evaluates the costs across the battery’s lifetime, to analyze two
classes of asymmetric chemistries, those with active species of finite or
infinite lifetimes, and their respective remediation options. For finite-lifetime
chemistries, we explore active-species replacement to counter decay. For
infinite-lifetime chemistries, we consider two methods for addressing
crossover: imposition of pseudo-symmetry via the spectator strategy and
elimination of crossover via membranes with perfect selectivity. We anticipate
this framework will help guide the evaluation and design of new redox
chemistries, balancing the desire for low capital costs with the need to
remediate capacity repeatedly and inexpensively.</p>