Even today, the infrastructure “represents billions of dollars in investment [and] huge growth in manufacturing capacity for lithium-ion,” said Rawles.

“You might have cell technology that would be cheaper in terms of raw materials theoretically, but to get to the cost that lithium-ion is at now would take huge investment and isn’t likely to happen," he said.

This may help explain the sluggish progress being made by a host of lithium-ion contenders banking on lower material costs to gain a competitive edge. 

Eos Energy Storage, which claims it can provide utility-scale battery storage for $160 per kilowatt-hour thanks to a chemistry based on a zinc hybrid cathode design, has managed to win orders from utilities such as Engie and Con Ed, but is hardly shipping massive quantities.

It is doing better than most, though. Ambri, with a liquid metal battery made from inexpensive, earth-abundant materials, is still in the early stages of commercialization despite raising $50 million in venture capital.  

Ecoult, which is touting an advanced lead-acid battery design, earlier this year announced its first steps in creating a global manufacturing network, but does not expect to have licensing deals in place in most energy storage markets until 2019. 

And the saltwater battery maker Aquion ran into well-publicized problems earlier this year. In July, it seemed to be back in business after its brush with death. Only time will tell whether the company can grow under its new ownership, however. 

Even established non-lithium-ion battery technologies, such as the sodium-sulfur chemistries sold by NGK and others, are having a hard time competing with lithium-ion’s vast market dominance.

Based on U.S. Department of Energy figures cited by the International Renewable Energy Agency, only 4.8 megawatts of sodium-based battery power capacity was announced, contracted or under construction as of this year, against more than 333 megawatts of lithium-ion storage. 

Flow batteries face a similar problem. Only one chemistry, vanadium redox, has become established. But International Renewable Energy Agency data shows the chemistry accounted for less than 1 percent of global electrochemical storage power capacity by mid-2017.

Furthermore, some observers believe that if used widely the flow battery chemistry would run into similar supply chain problems as those being flagged for lithium-ion. “There are limits to vanadium,” commented Hugh Sharman, principal at energy consultancy Incoteco.

“The ores are already getting thinner, and if vanadium becomes a major component of energy storage systems, then the price would skyrocket," he said.

Because of this, some flow battery makers have swerved toward chemistries based on more common elements. Energy Storage Systems, for instance, makes a flow battery in which iron is the main component. 

The concept looks great on paper but, yet again, is struggling against lithium-ion.

The only categories of energy storage that seem capable of holding their own in the face of lithium-ion’s electrochemical dominance are those that can deliver truly massive levels of capacity, such as pumped hydro, compressed air, molten salt or flywheels.

These rely on storage media that are so cheap they are practically free in some cases. And that might be the only thing that keeps them in the game as lithium-ion scales toward multi-gigawatt-hour levels.

After all, said Sharman: “Unless a cost-effective way is found to recycle the components, the practical limit for a lithium-ion battery will be materials-related. It won’t be related to economies of scale.”

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