I'd also say the 2 techs that are interesting less for their density aspect and more for longevity are flow batteries and liquid metal batteries. Both would solely be used for grid storage (Flow MIGHT be used for home storage).
Flow batteries are interesting because they have an very long cycle life and their storage capacity is based on how big a holding tank you have (fill the tank, get more storage). They are less interesting because they require mechanical pumps to operate.
Liquid metal batteries are interesting because of their cycle life and they are made out of pretty cheap materials. They are less interesting because they have very high operating temperature requirements.
I'd also say the 2 techs that are interesting less for their density aspect and more for longevity are flow batteries and liquid metal batteries. Both would solely be used for grid storage (Flow MIGHT be used for home storage).
Flow batteries are interesting because they have an very long cycle life and their storage capacity is based on how big a holding tank you have (fill the tank, get more storage). They are less interesting because they require mechanical pumps to operate.
Liquid metal batteries are interesting because of their cycle life and they are made out of pretty cheap materials. They are less interesting because they have very high operating temperature requirements.