As the world shifts to new energy sources, the competition between sodium-ion and lithium-ion batteries is intensifying. Currently, lithium-ion batteries lead the market, but sodium-ion batteries are gaining attention due to some appealing advantages. Let’s explore what makes each unique, their pros and cons, and their potential future directions.
What Are Sodium-ion Batteries?
The sodium-ion battery (SIB) is a recharged battery using sodium ions (Na⁺) as charge carriers. It comprises a sodium-containing cathode, an anode, and a liquid electrolyte. During charging, sodium ions are extracted and inserted into the anode, while discharging occurs reversely.
There are various types of Sodium-ion batteries, including NaMnO2, Na3V2(PO4)2F3 and Na2FeFe(CN)6.
NaMnO₂ (Layered Oxide)
- Working Voltage: 3.2 V; operational range: -40°C to 80°C.
- Cycle Life: Up to 4,500 cycles in lab prototypes with structural optimization (e.g., boron doping).
- Challenges: Rapid capacity decay (20 cycles) due to Mn³⁺ phase transitions; modified variants improve stability.
Na₃V₂(PO₄)₂F₃ (NVPF, NASICON-type)
- Energy Density: 75 Wh/kg at 1C rate; high voltage plateaus at 3.7 V and 4.2 V.
- Cycle Stability: Over 4,000 cycles in full-cell configurations due to carbon coatings and electrolyte additives (e.g., FEC).
- Applications: Suitable for grid storage and EVs due to thermal resilience and long lifespan.
Na₂FeFe(CN)₆ (Prussian White)
- Performance: Achieves 160 Wh/kg energy density with 3,000 cycles when paired with hard carbon anodes; benefits from fast Na⁺ diffusion in a cubic framework.
- Advantages: Low-temperature compatibility (-20°C with 80% capacity retention) and scalable synthesis, commercialized by CATL.
What Are Lithium-ion Batteries?
Lithium-ion batteries have evolved significantly over the years, with the first developed in the 1970s. They consist of four main components: cathode, anode, electrolyte, and separator.
The cathode determines capacity and voltage, while the anode directs electrons through a wire. The chất điện phân enables lithium ion movement between the cathode and anode for safe electricity flow. High ionic conductivity materials facilitate this movement, which varies based on electrolyte type.
There are six main types of lithium batteries; more information can be found here.
Sodium-ion Battery vs Lithium-ion Battery
When comparing sodium-ion and lithium-ion batteries, a comparison table offers a clear view of their differences.
| Features | Sodium-ion Battery | Lithium-ion Battery |
| Material Availability | Abundant | Limited |
| Tác động môi trường | Eco-friendly | Less eco-friendly |
| Trị giá | Cheap | Cao |
| Phạm vi nhiệt độ hoạt động | Cao hơn | Cao |
| Vòng đời | Cao | Cao |
| Power Density | Thấp | Cao |
| Charge Time | Nhanh hơn | Fast |
Challenges for Sodium-ion Battery
Sodium-ion battery manufacturing faces several challenges before it can replace lithium-ion batteries.
- There is no established supply chain for materials, and few companies are involved, leading to higher costs.
- The technology is still developing, limiting design flexibility and resulting in lower density and storage capacity compared to lithium batteries.
- Sodium-ion batteries have a cycle life of 5,000 cycles, significantly lower than the 6,000 cycles of commercial lithium iron phosphate batteries.
Can Sodium-based Batteries Replace Lithium-ion Batteries?
Sodium-ion batteries could be a great alternative to lithium-ion ones, but they face some hurdles before they can truly take off.
To become the go-to choice for energy storage, they need to improve their technical performance. Researchers are working hard to make these batteries more stable and affordable, while companies are busy establishing a solid supply chain for the necessary materials.
