How US battery startup Alsym Energy’s sodium-ion systems aim to go where LFP cannot

Na-ion is widely seen as the next to commercialise at scale and provide an alternative to lithium-ion (Li-ion).

Sodium is significantly cheaper and more plentiful than lithium. Na-ion batteries cannot reach the energy densities of Li-ion batteries and are likely to have fewer charge cycles.

Nevertheless, they could be more affordable if produced in large quantities, and they are also believed to carry a reduced risk of thermal runaway.

Sodium-ion BESS startups such as Moonwatt in Europe and Peak Energy in the US will highlight a substantial increase in manufacturing in China, along with its significantly lower theoretical cost compared to lithium-ion.

However, competing with Li-ion is not an easy task. Evan Hartley, research manager at battery materials intelligence firm Benchmark Mineral Intelligence, highlighted in a September interview with ESN Premium the challenges faced by US Na-ion battery firm Natron Energy prior to its closure.

“It’s a general trend across the market of those market entrants struggling. They were targeting sodium-ion, which meant they had a much lower pool of demand to target. We are expecting no more than 3-4GWh of demand for sodium-ion in North America by the end of the decade. That could change, but it depends on price,” Hartley explained.

Alsym is banking on its “low-cost, high-performance rechargeable” mystery battery chemistry.

In 2024, the company raised US$78 million in venture capital funding from Tata Sons. Alsym said it would use that funding for its first product, Alsym Green claimed to provide a superior system-level energy density compared to other non-lithium battery chemistries. It stated its applicability for stationary energy storage, as well as maritime and automotive use, including two- and three-wheelers and consumer vehicles.

Alsym’s Na-Series

In October, Alysm announced the launch of its Na-Series energy storage battery. The company claims it is purpose-built for energy storage and offers “a non-flammable, non-toxic, and cost-effective solution to meet the surging demand for power driven by data centres, electrification, and accelerating renewable energy deployment.”

Chatter explained that part of the challenge of launching the system has been stress on energy storage supply chains. This applied not only to the US, but also to Alsym.

Market research firm Wood Mackenzie’s report, ‘All aboard the tariff coaster: implications for the US power industry,’ states that tariffs on imports will mostly affect battery storage more than solar PV or wind sectors.

 The reason for this is that the battery energy storage system (BESS) market relies heavily on imports from China, with “nearly all” battery cells for US utility-scale projects in 2024 coming from there. Depending on how much tariffs increase, the cost of utility-scale BESS could rise by 12% to 50% across three projected tariff scenarios.

From a multitude of market challenges, Chatter explains, “We decided that we are going to focus more on things that are supply chain independent, meaning we are not dependent on China for our supply chain. The Na-Series is a new series that we came up with.”

He continues, “The good news is that the performance dimension is much higher, with significantly increased charge and discharge rates. This broadens its applicability to a wider range of uses, including not only traditional grid storage but also data centres and industrial applications within buildings.”

Chatter also emphasises the cost-competitive advantage that Alsym claims the NA-Series possesses.

The CEO credits this advantage, at least in part, to the company’s revamped supply chain.

“It offers significantly higher performance than any other Na-ion battery and is more affordable, primarily because materials like sodium carbonate (soda ash), widely available in Wyoming, are much cheaper locally than processed lithium. Therefore, its cost will be competitive with LFP batteries,” he says.

Chatter highlights additional benefits of the company’s batteries, claiming, “we will also have the UL9540A certification at the cell level, which LFP cannot achieve. This underscores the focus on non-flammability, non-toxicity, cost competitiveness, and an extended temperature range.”

Earlier this year, UL Solutions revised its fire safety testing for battery storage to align with updates to the UL9540A test method. It assesses the probability of thermal runaway happening via various causes, including physical abuse or short circuits, and also considers the potential for fire spread once it occurs.

Flammability and temperature range

For Chatter, a big advantage that Alsym has is in its non-flammability when compared to LFP.

He explains, “Our product can be installed inside, on top of, or attached to commercial buildings. I mention these options because LFP doesn’t support this flexibility. Additionally, New York City passed Local Law 97 (LL97) last year, which requires reducing emissions of large buildings by about 40%.”

Chatter asks, “How can you meet emissions goals if you cannot place storage in crowded areas like New York City (NYC), Boston, LA, or San Francisco?”

NYC enforces some of the strictest fire safety regulations for energy storage in the US, due to its densely populated urban environment.

Chatter clarifies, “I think LFP is a good application for low-density applications. But, if you go to high-density applications, 200kWh, 1MWh, multi-MWh, it’s just too dangerous.”

Alsym’s co-founder also says that the systems do not require the same amount of cooling that LFP systems do.

Peak Energy, which recently announced a multi-year phased agreement with developer Jupiter Power to supply up to 4.75GWh of Na-ion BESS, makes similar claims for its systems.

Lithium-based BESS units require active cooling and ventilation to prolong cell life and prevent fires. Peak Energy’s BESS is designed with no moving parts and includes active cooling and ventilation systems, which the company states help avoid the most frequent failure points found in standard BESS configurations.

Chatter continues of LFP and Na-ion, “Na-ion can comfortably operate at ambient temperatures up to 50 degrees Celsius. In hot climates like California or Texas, once temperatures reach around 43 degrees Celsius, you need to shut LFP systems down because it’s too hot. Since it’s based on LFP technology, during the times you need it most, such as in extreme heat, you’ll actually have the least performance.”

Alsym’s systems have not yet been proven at a utility scale, but Chatter reports that the company plans to deliver both cells and modules to customers in the first half of 2026.

He says they will be 1KWh modules, and after testing, progressively larger modules will be shipped out, potentially in mid-2027.

Chatter says, “Our technology is fully compatible with facilities that produce lithium-ion cells. We are reaching out to companies with excess capacity that could implement it.”

He continues, “While it is relatively straightforward to do this in China or Korea, our goal is to accomplish it within the United States if possible. There are significant advantages in terms of applications and potential destinations, especially considering supply chain challenges.”