CATL’s sodium-ion batteries are about to hit mass production, with full-scale manufacturing set for December 2025 and early BESS pilots starting in 2026. Backed by the world’s largest battery maker, they’re aimed at EVs and short-duration grid storage.
Let’s look at how they stack up against $EOSE zinc batteries, and whether sodium-ion can really take over the BESS market.
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CATL's energy density stands out. Naxtra reaches 175 Wh/kg, nearly twice $EOSE Z3's 70–100 Wh/kg, allowing for more compact EV packs with 500+ km range or efficient grid installations that outperform zinc in density.
This advantage supports applications where space and weight are critical.
2/11
Safety matters. Lithium systems carry thermal runaway and fire risks that demand complex fire suppression, spacing, and insurance premiums. Both sodium and zinc avoid this, using non-flammable chemistries that cut site costs and simplify permitting.
On safety alone, sodium appears to match one of $EOSE zinc’s biggest advantages.
3/11
CATL targets
This combination of cost and scale positions sodium for widespread adoption.
4/11
CATL is already deploying in Chery and Li Auto EVs, plus BYD's 2-4 hour BESS pilots. Strong cold-weather performance and fast charge cycles make it ideal for mobility and short peak-shaving.
On the surface, momentum looks squarely in CATL’s favor.
5/11
Here is where assumptions start breaking.
Sodium excels in 1-6 hour windows, not long-duration. Its 90-95% DoD (how much stored energy can actually be used) and voltage sag mean roughly 30% more capacity is needed for true 12-hour output.
In simple terms: to deliver the same long run, you need more batteries, more inverters, and more balance-of-plant. Eos Z3 runs 100% DoD with stable discharge.
Different chemistries, different jobs.
6/11
For LDES (Long-Duration Energy System), CATL's fast charging benefits EVs, yet $EOSE Z3's aqueous electrolyte enables non-flammable operation with steady voltage over 3-12+ hours without the efficiency losses from cooling.
This supports reliable multi-hour renewable integration.
7/11
In LDES economics, $EOSE avoids oversizing needs, achieving <$100/kWh installed via 45X credits—backed by a $303.5M DOE loan for 8 GWh domestic production by 2026, reducing import vulnerabilities.
The IRA prioritizes such domestic solutions.
8/11
In the broader grid context, 80-90% renewables by 2050 will involve multi-day lulls from low wind or solar. Sodium handles 4-hour peaks effectively, but $EOSE addresses 10+ hour gaps for system reliability.
DOE/NREL project 225-460 GW LDES by 2050;
energy.gov/lpo/articles/s…
California and New York require multi-day capabilities.
formenergy.com/wp-content/upl…
9/11
Overbuilding renewables to cover lulls would require massive excess capacity and curtailment. For LDES, EOSE Z3 offers strong energy delivery for multi-hour to multi-day needs.
CATL's expansion accelerates renewables adoption, creating more long-duration opportunities for $EOSE
10/11
The takeaway: CATL’s sodium-ion is built for scale and speed, perfect for EVs and short-duration BESS. EOSE zinc tech is built for endurance, the backbone of 12+ hour, fire-safe, domestic storage.
As renewables grow, both will thrive. CATL powers the transition. $EOSE keeps it running when the sun sets. ⚡️
11/11
#EnergyStorage #LDES #EOSE
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