“The researcher’s tests demonstrated that the resulting battery design can have an extremely long life, with the battery retaining 99 percent of its original capacity after 10,000 charge/discharge cycles.”
A salt additive lets an aluminum-ion battery keep 99% capacity after 10,000 cycles. Aluminum costs about a quarter as much as lithium. The energy density is still too low for commercial use. That is the part every battery breakthrough skips.