Sodium-ion battery
A rechargeable battery analogous to lithium-ion but using abundant sodium ions, trading energy density for lower material cost and better cold performance.
A sodium-ion battery works on the same rocking-chair principle as lithium-ion, but Na+ ions move between electrodes. Because sodium ions are too large to intercalate efficiently in graphite, the anode is usually hard carbon. Cathodes include layered transition-metal oxides, Prussian blue analogues and polyanionic compounds such as sodium vanadium phosphate.
Cell energy density: about 100–175 Wh/kg (2024–2025 commercial cells)
Cycle life: roughly 2,000–6,000 cycles depending on chemistry
Advantages: sodium is around a thousand times more abundant than lithium in the Earth's crust; aluminium can be used for both current collectors (copper is unnecessary on the anode side); cells retain about 85–90% capacity at -20 °C; and they can be stored and shipped at 0 V, improving safety. Disadvantages are lower energy density than LFP and an immature supply chain.
Mass production began in China in 2023–2024 (CATL, BYD, HiNa), targeting small EVs, two-wheelers and stationary storage. Cost parity with LFP depends heavily on lithium prices; when lithium carbonate collapsed in 2023–2024 the short-term cost advantage narrowed.
Related terms
All terms →- Lithium-ion battery
A rechargeable battery in which lithium ions shuttle between a graphite anode and a metal-oxide or phosphate cathode; the dominant chemistry for EVs and grid storage.
- LFP (Lithium Iron Phosphate)
A lithium-ion cathode chemistry (LiFePO4) prized for safety, long cycle life and low cost, at the expense of lower energy density than nickel-based cells.
- Flow battery
An electrochemical battery storing energy in liquid electrolytes held in external tanks, so power (stack size) and energy (tank volume) scale independently.
- Energy density
The amount of energy stored per unit mass (specific energy, Wh/kg or MJ/kg) or per unit volume (Wh/L or MJ/L) of a fuel or storage medium.
- BESS (Battery Energy Storage System)
A complete grid- or site-connected battery installation, including cells, battery management, power conversion, thermal management and controls.