# Sodium-ion batteries: Science and technology

How sodium swaps in for lithium, and what it costs in energy

Source page: https://www.materialinsights.org/energy/e_sodium_ion/sg-sci/

What this tab covers The physics and chemistry: how the energy is stored, which materials it needs (scarcity, toxicity, recyclability) and what makes it age.

Sodium-ion works like lithium-ion but shuttles sodium ions, an element about 1,000 times more abundant in the Earth's crust. It stores less energy per kilogram than LFP but tolerates cold and can be shipped fully discharged.

#### Mechanism
Favourable

Sodium ions move between a hard carbon anode (a disordered carbon, since sodium does not fit well into graphite) and one of three cathode families: layered metal oxides, polyanion compounds such as iron phosphates, or Prussian blue analogues (cheap iron-cyanide frameworks). Because sodium does not alloy with aluminium at low voltage, aluminium foil can be used on both electrodes instead of copper on the anode, saving cost. Mass-produced cells store 90 to 160 Wh/kg; CATL says its Naxtra cell reaches 175 Wh/kg, against up to 205 Wh/kg for LFP.^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf)^[2](https://iea.org/reports/global-ev-outlook-2026/electric-vehicle-batteries)
 Mass-produced energy density 90-160 Wh/kg^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf) Best commercial cell (CATL Naxtra, company figure) 175 Wh/kg^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf) LFP for comparison up to 205 Wh/kg^[2](https://iea.org/reports/global-ev-outlook-2026/electric-vehicle-batteries) Hard carbon anode capacity about 300 mAh/g^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf)

#### Material scarcity and toxicity
Favourable

Sodium comes from soda ash, with natural resources estimated at 47 billion tonnes, and it can also be made from salt and limestone. Between 2020 and 2024 sodium carbonate cost USD 100 to 500 a tonne while lithium carbonate swung between USD 6,000 and 83,000. Prussian white and polyanion cathodes contain no cobalt or nickel, although some layered oxides still use nickel. The weak link is concentration of manufacturing: China holds over 95% of announced production capacity, and the hard carbon anode supply chain is immature and also concentrated in China.^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf)^[2](https://iea.org/reports/global-ev-outlook-2026/electric-vehicle-batteries)
 Crustal abundance relative to lithium about 1,000 times^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf) Sodium carbonate price, 2020-2024 USD 100-500/t^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf) Lithium carbonate price, 2020-2024 USD 6,000-83,000/t^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf) China share of announced production capacity over 95%^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf)

#### Degradation and ageing
Mixed

Layered oxide cathodes lose capacity through repeated crystal phase changes and air sensitivity, Prussian blue materials degrade if water is left in the lattice, and the hard carbon anode loses sodium to surface film growth. IRENA reports cycle life of 500 to 8,000 cycles across products and a calendar life of 10 to 15 years, with leading cells keeping 80% of capacity after 4,000 to 5,000 cycles. CATL claims over 10,000 cycles to 80% health for Naxtra, and over 15,000 cycles to 70% health at 25 C for its Tener Sodium grid system launched in June 2026 (company claims). The wide range reflects very different chemistries sold under one name, so buyers need chemistry-specific test data.^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf)^[3](https://www.eesc.europa.eu/sites/default/files/2026-06/qe-01-26-008-en-n.pdf)^[10](https://cnevpost.com/2026/06/22/catl-unveils-tener-sodium/)
 Cycle life range 500-8,000 cycles^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf) Calendar life 10-15 years^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf) CATL Naxtra claim (company) over 10,000 cycles to 80% health^[3](https://www.eesc.europa.eu/sites/default/files/2026-06/qe-01-26-008-en-n.pdf) CATL Tener Sodium grid system claim (2026) 15,000 cycles to 70% health at 25 C^[10](https://cnevpost.com/2026/06/22/catl-unveils-tener-sodium/)

#### Cathode families compared^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf)

| Cathode family | Example specific capacity | Cobalt or nickel | Notes |
|---|---|---|---|
| **Layered oxide** | 105-132 mAh/g (examples) | Often nickel, sometimes cobalt | Dominates 2025 production capacity |
| **Polyanion (e.g. iron phosphates)** | 125-130 mAh/g (examples) | None | Stable, long life, lower energy |
| **Prussian blue analogue** | 150 mAh/g at about 3.5 V | None in Prussian white types | Very cheap materials; water control critical |

#### Sources

1. [Sodium-ion batteries: Technology brief](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2025/Nov/IRENA_TEC_Sodium-ion_batteries_2025.pdf) IRENA, 2025
2. [Global EV Outlook 2026: Electric vehicle batteries](https://iea.org/reports/global-ev-outlook-2026/electric-vehicle-batteries) International Energy Agency, 2026
3. [Energy resilience of households in a prepared union: the potential of a sodium battery-based solution (study by Milieu, WSP and CE Delft)](https://www.eesc.europa.eu/sites/default/files/2026-06/qe-01-26-008-en-n.pdf) European Economic and Social Committee, 2026
4. [CATL pushes sodium energy storage to market with Tener Sodium launch (company claims)](https://cnevpost.com/2026/06/22/catl-unveils-tener-sodium/) CnEVPost, 2026

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_sodium_ion/index.md)
- [Overview](https://www.materialinsights.org/energy/e_sodium_ion/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_sodium_ion/correlation/index.md)
- [Engineering and performance](https://www.materialinsights.org/energy/e_sodium_ion/sg-eng/index.md)
- [Economics](https://www.materialinsights.org/energy/e_sodium_ion/sg-econ/index.md)
- [Impact and additionality](https://www.materialinsights.org/energy/e_sodium_ion/sg-impact/index.md)
- [What to track](https://www.materialinsights.org/energy/e_sodium_ion/tracking/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_sodium_ion/links/index.md)