Sodium-ion vs Lithium-ion Battery

Sodium-ion batteries mainly consist of a positive electrode, a negative electrode, a separator, a current collector, and an electrolyte. Based on whether their constituent materials directly participate in the electrochemical reaction, they can be divided into active and inactive materials. Active materials include the positive electrode material, negative electrode material, and electrolyte material, while inactive materials include the separator, current collector, conductive agent, and binder.

Sodium Battery Working Principle

The working principle of sodium-ion batteries is similar to that of lithium-ion batteries, both belonging to the "rocking chair" method. During charging, sodium ions are released from the positive electrode material and inserted into the negative electrode material via the electrolyte. Simultaneously, electrons move from the positive electrode to the negative electrode through the external circuit to maintain the charge balance of the entire system. The discharging process is the reverse of the charging process. The positive and negative electrode material system is the decisive factor in sodium-ion battery use, and the electrolyte is mainly selected and matched with the positive and negative electrode material system.

Comparison of Sodium-ion Batteries and Lithium-ion Batteries

Although sodium and lithium are both alkali metals, their physical properties are quite different. When engineers use sodium and lithium in battery applications, these inherent differences directly affect their electrochemical behavior. As two distinct rechargeable battery technologies, sodium-ion and lithium-ion batteries each have their own advantages and disadvantages in various aspects.

Sodium vs. Lithium Battery Chemistry

Sodium-ion Battery (Important System Information Block)

Cathode Material: Sodium compounds of transition metal oxides (e.g., NaFeO₂), phosphates (NaFePO₃), sulfates (Na₂Fe₂(SO₄)₃), and Prussian blue analogs (Na₂Fe[Fe(CN)₆]).

Anode Material: Specially designed carbon materials—hard and soft carbon with stable sodium ion storage.

Working Principle: During charging, sodium ions move from the cathode to the anode and deposit in the carbon structure. During discharging, sodium ions move to the cathode, releasing energy to charge the device.

Lithium-ion batteries (Li-ion batteries)

Cathode materials: Lithium-containing materials, such as lithium cobalt oxide (LiCoO₂), lithium iron phosphate (LiFePO₄), and lithium nickel manganese cobalt oxide (NMC).

Anode materials: Graphite is the most common choice, but some newer models use silicon or lithium titanate (LTO) to improve performance.

Working principle: During charging, lithium ions migrate from the cathode to the anode and are sandwiched between graphite layers. During discharging, lithium ions return to the cathode, generating current.

Sodium-ion batteries vs. lithium-ion batteries: Cost comparison

Theoretically, sodium-ion batteries have the advantage of lower material costs. Sodium accounts for 2.3% of the Earth's crust, only 0.0065 times that of lithium (400%), and its global distribution is more uniform. Sodium batteries use inexpensive aluminum foil at both electrodes, potentially reducing material costs by 30-40% compared to lithium-ion batteries.

However, the reality is far from optimistic: sodium battery manufacturers have yet to achieve mass production, while the price of lithium iron phosphate (LFP) batteries continues to fall, expected to bottom out in 2025. These factors have virtually eliminated the cost gap.

Performance Comparison of Sodium and Lithium Batteries

While traditional lithium batteries perform poorly in cold environments, sodium-ion battery technology can maintain 30% of its discharge capacity at -92°C, completely solving the problem of poor lithium battery performance in cold weather. CATL's sodium-ion batteries can be charged to 15% in just 80 minutes at room temperature and operate stably in temperatures ranging from -40°C to 80°C. However, sodium-ion batteries are heavier and have lower energy density, currently limiting their application to low-speed vehicles.

Standard lithium batteries perform best in the 20-30°C range; performance degrades beyond this range. CMB's innovative solution? Customized lithium battery packs with wide operating temperature (-20°C to 85°C) and waterproof, heat-resistant BMS technology. This innovation bridges the gap between the temperature adaptability of sodium-ion batteries and the energy density of lithium-ion batteries, providing reliable power in the event of standard battery failure.

Frequently Asked Questions about Sodium and Lithium Batteries

1. Why are sodium-ion batteries often compared to lithium iron phosphate batteries?

Because sodium-ion batteries have a lower energy density than the nickel-based chemistry commonly used in lithium-ion batteries. Therefore, sodium-ion batteries are better suited for applications with lower energy demands. Would you like to adjust this statement further? This makes them ideal for stationary energy storage systems and small vehicles where range is not critical. Notably, BYD in China plans to use sodium-ion batteries in its "microcars," clearly indicating its target market.

2. Are sodium-ion batteries really cheaper than lithium-ion batteries?

Lithium-ion battery prices soared due to supply chain disruptions during the COVID-19 pandemic and geopolitical tensions affecting nickel supply, bringing sodium-ion technology into the spotlight.

However, the situation has changed. Over time, data suggests that the price of lithium-ion batteries could fall below $2027 per kilowatt-hour (kWh) by 100 years. Lithium iron phosphate batteries will become increasingly cheaper.

3. Can sodium-ion batteries replace lead-acid batteries in terms of peak starting power?

Generally speaking, they can be replaced at any time. Even a standard 2Ah lithium-ion battery drill bit can provide better starting performance for a 3kW diesel starter.

4. Do you recommend sodium-ion battery packs?

It depends on the specific application. However, considering that the cost is currently almost the same, I recommend using lithium-ion battery packs, which have higher energy density and longer cycle life. Sodium-ion battery packs are also cheaper and safer in low-temperature climates. CMB is committed to providing customized lithium battery pack solutions to meet your different needs. Welcome to contact us for professional solutions.