Weight, Energy density. and cost are what's most important for general Electric car energy storage. So if this cost's more or weights significantly more it's next to useless for that. However, they might have some use as part of a more efficient regenerative breaking system.
PS: As to faster charging, issues are going to Limit that. A 99% efficient battery charging 100x as fast as Li-Ion is going to dump a lot of heat vary quickly. Duping heat is not really an issue for small battery's but scale this up into the 50+kwh range for an electric car or even just a cellphone battery and you will have significant issues.
About charging speed, you're invoking another problem, that of (over)heating. That however, deserves a separate context of its own to be addressed in. I think it's safe to assume that a lot of efficiency can be safely salvaged from that 100x improvement.
PS: As to faster charging, issues are going to Limit that. A 99% efficient battery charging 100x as fast as Li-Ion is going to dump a lot of heat vary quickly. Duping heat is not really an issue for small battery's but scale this up into the 50+kwh range for an electric car or even just a cellphone battery and you will have significant issues.