Sodium-Ion Batteries Show Promise as a Lithium-Free Future

Sodium-ion batteries are emerging as a safer, more sustainable alternative to lithium-ion. Learn about the latest advancements

THUNDER BAY – TECHNOLOGY – Lithium-ion batteries power much of modern life, from electric vehicles (EVs) and e-bikes to smartphones and power tools. However, concerns over lithium’s environmental impact, fire risks, and resource scarcity are driving the search for safer and more sustainable alternatives. One of the most promising contenders is sodium-ion batteries, which offer a lower-cost and more abundant solution.

The Risks of Lithium-Ion Batteries

While lithium-ion technology has revolutionized energy storage, it is not without risks:

• Fire Hazards – Lithium-ion batteries can overheat and, in some cases, catch fire or explode, as seen in e-bike and EV incidents.
• Environmental Impact – Lithium mining consumes large amounts of water and can lead to environmental degradation.
• Supply Chain Issues – Lithium is primarily sourced from a few countries, leading to potential shortages and price volatility.

TTC Implements Winter Ban on E-Bikes and E-Scooters Due to Battery Fire Risks

In a move to enhance passenger safety, the Toronto Transit Commission (TTC) has approved a seasonal ban on e-bikes and e-scooters equipped with lithium-ion batteries. This decision stems from concerns over potential fire hazards associated with these devices during the winter months.

Details of the Ban

• Effective Period: The ban is in effect annually from November 15 to April 15.​

• Scope: All e-bikes and e-scooters powered by lithium-ion batteries are prohibited inside TTC stations, facilities, and on TTC vehicles during this period. ​

Rationale Behind the Decision

The TTC’s decision follows incidents highlighting the fire risks posed by lithium-ion batteries, particularly in colder conditions where battery failures can lead to thermal runaway events. An investigation into a previous incident revealed that a battery failure resulted in a fire, prompting the TTC to take preventive measures.

What Happens When a Lithium-Ion Battery Burns?

When a lithium-ion battery catches fire, it undergoes a dangerous process called thermal runaway, which can lead to explosions, toxic gas release, and intense fires that are difficult to extinguish. Here’s a breakdown of what happens:

1. Overheating and Thermal Runaway

• A short circuit, overcharging, physical damage, or exposure to high temperatures can cause the battery’s internal temperature to rise.
• Once the battery reaches around 150°C (302°F), its electrolyte begins to break down, releasing flammable gases.
• If the heat continues to build, it triggers thermal runaway, an uncontrollable reaction where the temperature keeps rising, feeding the fire.

2. Fire and Explosion

• The flammable electrolyte ignites, causing intense flames and possibly an explosion.
• In some cases, a pressure build-up inside the battery casing leads to a violent rupture.
• The fire can spread to nearby battery cells, causing a chain reaction.

3. Toxic Gas Release

• Burning lithium-ion batteries emit highly toxic gases, including:
  • Hydrogen fluoride (HF) – A deadly gas that can cause severe lung damage.
  • Carbon monoxide (CO) – A poisonous gas that reduces oxygen in the bloodstream.
  • Other volatile organic compounds (VOCs) that contribute to air contamination.

4. Difficult to Extinguish

• Water alone is not effective—lithium fires can continue burning even without oxygen.
• Special Class D fire extinguishers (for metal fires) or lithium-ion battery fire blankets are required to contain the flames.
• The safest method is to let the battery burn out in a controlled area while cooling surrounding materials to prevent the fire from spreading.

5. Environmental and Safety Hazards

• The aftermath of a lithium battery fire leaves toxic residue that contaminates air, water, and soil.
• Firefighters and bystanders are at risk of exposure to harmful gases and explosions.
• Damaged batteries in landfills or recycling facilities can ignite, causing hazardous waste fires.

Sodium-Ion Batteries: A Game-Changer?

Sodium-ion batteries function similarly to lithium-ion but use sodium instead of lithium. The key advantages of sodium-ion technology include:

• Abundance – Sodium is widely available and can be sourced from seawater, reducing dependency on scarce lithium.
• Lower Cost – Sodium-ion batteries are cheaper to produce due to the abundance of raw materials.
• Enhanced Safety – They are less prone to overheating and catching fire compared to lithium-ion batteries.

What is Needed to Produce a Sodium-Ion Battery?

Sodium-ion batteries (SIBs) share a similar structure to lithium-ion batteries (LIBs) but use sodium instead of lithium as the primary charge carrier. To produce a sodium-ion battery, the following key components and materials are required:

1. Raw Materials

• Sodium (Na) – The main element, which can be sourced from abundant and low-cost materials like seawater or soda ash.
• Cathode Materials – Typically made from sodium-based compounds such as:
  • Sodium iron phosphate (NaFePO₄)
  • Sodium manganese oxide (Na₂Mn₃O₇)
  • Layered metal oxides (e.g., NaNiMnCoO₂)
• Anode Materials – Unlike lithium-ion batteries, which use graphite, sodium-ion batteries often use:
  • Hard carbon (produced from biomass or industrial waste)
  • Tin or antimony-based compounds (for higher capacity)
• Electrolyte – A sodium-based salt dissolved in a liquid solvent (e.g., sodium perchlorate or sodium hexafluorophosphate in organic solvents).
• Separator – A thin, porous membrane that prevents direct contact between the anode and cathode while allowing sodium ions to flow through.

2. Manufacturing Process

• Material Synthesis – The cathode and anode materials are synthesized and processed to ensure optimal performance.
• Electrode Coating – The anode and cathode materials are coated onto metal foils (typically aluminum for both, unlike lithium-ion, which uses copper for the anode).
• Battery Cell Assembly – Electrodes, separators, and electrolytes are placed into a casing, which can be in cylindrical, pouch, or prismatic form.
• Electrolyte Filling & Sealing – Electrolyte is injected, and the battery cell is sealed.
• Formation & Testing – Initial charging cycles help stabilize the battery, followed by quality control testing.

3. Infrastructure and Equipment

• Battery manufacturing facilities – Similar to lithium-ion factories but adapted for sodium-ion chemistry.
• Supply chain logistics – Access to raw materials, refining processes, and transportation.
• Recycling capabilities – Sodium-ion batteries have an easier recycling process than lithium-ion, requiring infrastructure to handle end-of-life batteries.

4. Research and Development

• Enhancing energy density – Sodium-ion batteries currently have lower energy storage than lithium-ion.
• Improving cycle life – Extending the number of charge cycles to compete with lithium-based batteries.
• Commercialization efforts – Scaling up production to make sodium-ion batteries cost-competitive with lithium alternatives.

How is Research Progressing?

Several companies and research institutions are making significant progress in sodium-ion battery technology:

• CATL (China’s leading battery maker) is developing sodium-ion batteries for EVs, with commercial models expected soon.
• European and North American firms are investing in sodium-based energy storage solutions for grid applications.
• Researchers are improving energy density, though sodium-ion batteries currently have lower energy storage capacity than lithium-ion ones.

What Does This Mean for Thunder Bay?

As interest in clean energy and sustainable transportation grows, Northwestern Ontario could benefit from sodium-ion advancements. It also means being flexible in adapting new technology – including the political levels at the federal, municipal and provincial levels.

It could mean a shift in technology that will impact our city. Remember the huge excitement over the Thunder Bay Paper mill which was set up to produce high quality paper for catalogues?

That plant did exactly that, receiving significant government funding. The only problem was that technology was shifting and the move from paper to digital was moving faster than the thinking. Stockpiles of expensive and basically unsellable paper piled up until the plant closed.

Latching on to technology means keeping a very flexible handle on reality and keeping abreast of the latest and coming technologies.

The Future of Battery Technology

While sodium-ion batteries are not yet ready to completely replace lithium-ion technology, they are emerging as a strong alternative for specific applications. As research advances, these batteries could play a crucial role in making energy storage safer, cheaper, and more sustainable.