Sodium-ion Batteries: Rethinking battery strategy

Sodium-Ion Batteries are a strategic opportunity for India’s Energy Security. India relies heavily on Li-ion batteries, which can be reduced by changing strategy. Read here to learn more.

As batteries increasingly underpin electric mobility, renewable integration, and digital infrastructure, India’s heavy reliance on lithium-ion batteries (LiBs) exposes it to critical mineral dependency, geopolitical vulnerabilities, and supply-chain risks.

In this context, sodium-ion batteries (SiBs) are emerging as a strategically important alternative, offering India an opportunity to enhance energy security, cost competitiveness, and technological resilience.

What are Sodium-Ion Batteries?

Sodium-ion batteries (Na-ion batteries) are electrochemical energy storage systems that use sodium ions (Na⁺) instead of lithium ions for charge transfer between cathode and anode.

Key Features:

• Abundant Raw Material: Sodium is widely available from sea salt and soda ash.
• Cost-effective Chemistry: Does not rely on scarce minerals like lithium, cobalt, or nickel.
• Rapid Charging & Low-Temperature Performance
• Longer Cycle Stability (in certain chemistries)
• Enhanced Safety Profile

Sodium-Ion vs Lithium-Ion

1. Energy Density

Historically, SiBs had lower specific energy due to the heavier sodium ion.

However, modern layered transition-metal oxide cathodes are now approaching the performance of Lithium Iron Phosphate (LFP) batteries, narrowing the gap for applications like:

• Electric two- and three-wheelers
• Stationary grid storage

2. Safety

SiBs are intrinsically safer, exhibiting:

• Lower peak temperatures during thermal runaway
• Reduced fire propagation risk

3. Transportation & Logistics Advantage

Unlike lithium-ion batteries:

• SiBs can be stored and transported at zero volts
• They are not classified as hazardous in the same way as LiBs
• Lower insurance and logistics costs

This reduces supply-chain friction and improves safety compliance.

Strategic Significance for India

1. Reducing Import Dependence

Lithium-ion batteries depend on:

• Lithium (Chile, Australia, Argentina)
• Cobalt (DR Congo)
• Nickel (Indonesia)
• Graphite (China)

India imports most of these minerals, creating strategic vulnerabilities.

In contrast:

• Sodium is abundantly available.
• India has a strong domestic production of soda ash.
• Aluminium (used instead of copper as current collectors) is widely available.

SiBs can therefore enhance strategic autonomy and reduce exposure to global mineral cartels.

2. Cost Advantage for India’s Mass Market

• Use of aluminium instead of copper reduces cost.
• Avoidance of cobalt and nickel lowers raw material volatility.
• Suitable for price-sensitive segments:
  • Electric two-wheelers
  • Three-wheelers
  • E-buses
  • Grid storage

By the mid-2030s, cost projections indicate that SiBs may become cheaper than lithium-ion batteries, especially as scale improves.

3. Ease of Manufacturing Adoption

India’s PLI scheme for Advanced Chemistry Cells (ACC) has already created basic cell manufacturing infrastructure.

SiBs can:

• Leverage existing production lines
• Require only moderate process modifications
• Integrate into current battery ecosystems

This lowers transition barriers.

India’s Existing Battery Ecosystem Initiatives

1. PLI Scheme for ACC (50 GWh target)
   • 40 GWh awarded
   • Only ~1 GWh commissioned so far
   • Slow disbursement indicates execution bottlenecks
2. National Critical Minerals Mission
   • Focus on exploration, mining, and recycling
3. Khanij Bidesh India Limited (KABIL)
   • Overseas mineral acquisition
4. Battery Waste Management Rules 2022
   • Extended Producer Responsibility (EPR)

However, most policies remain lithium-centric, with limited explicit support for sodium-ion technology.

Challenges in Scaling Sodium-Ion Batteries

1. Lower Energy Density

• Higher weight reduces suitability for long-range EVs.
• Less ideal for compact passenger cars.

2. Manufacturing Sensitivity

• High moisture sensitivity
• Requires deeper vacuum drying
• Higher initial energy consumption in production

3. Underdeveloped Supply Chain

India lacks:

• Sodium-specific cathode manufacturers
• Anode (hard carbon) ecosystem
• Electrolyte and separator supply chains

Cell assembly alone is insufficient; upstream processing must scale.

4. Policy and Regulatory Gaps

• No dedicated sodium-ion incentives
• Absence of safety certification standards
• Limited clarity in FAME and EV policy alignment

5. Market Confidence Gap

• A few pilot deployments
• Limited OEM validation
• Investor hesitancy

Way forward for Scaling Sodium-Ion in India

1. Farm-to-Battery Hard Carbon Strategy

Hard carbon (anode material) can be derived from:

• Rice husk
• Coconut shells
• Agricultural residue

Establish pyrolysis units in:

• Punjab & Haryana (rice belts)
• Kerala & Tamil Nadu (coconut belts)

Benefits:

• Converts stubble burning into industrial feedstock
• Creates rural value chains
• Reduces imports of battery-grade hard carbon

2. Desert-Centric Manufacturing Clusters

Set up SiB gigafactories in:

• Rajasthan
• Kutch (Gujarat)

Low humidity:

• Reduces dry-room energy requirements
• Lowers operational costs
• Improves process stability

3. Strategic Market Entry via Standardisation

Instead of competing immediately in passenger EVs:

• Standardise sodium-ion packs for:
  • Three-wheelers
  • E-buses
  • Stationary storage

These segments tolerate:

• Larger battery size
• Slightly lower energy density

Scale first and optimise later.

4. Hybrid Sodium-Lithium Packs

Encourage dual chemistry systems:

• Sodium-ion for daily commute cycles
• Lithium-ion for peak performance and long range

Benefits:

• Reduces lithium usage
• Maintains vehicle performance
• Lowers overall cost

5. Chemical Upgrading Incentives

Support domestic chemical firms to:

• Upgrade soda ash to battery-grade sodium carbonate
• Build precursor refining capacity

This closes supply-chain gaps beyond cell assembly.

Broader Strategic Implications

Sodium-ion batteries align with:

• Atmanirbhar Bharat
• Make in India
• Energy Transition Goals
• Net Zero 2070 Roadmap

They offer India an opportunity to avoid becoming dependent on a lithium-dominated global order, much like dependence on fossil fuel imports in the past.

Conclusion

Sodium-ion batteries are not a replacement for lithium-ion technology but a strategic complement. For high-energy applications like premium EVs, lithium may remain dominant. However, for mass-market mobility and grid storage, sodium-ion batteries offer India a pathway to:

• Reduce import dependence
• Enhance energy security
• Lower costs
• Build domestic manufacturing ecosystems

Early policy clarity, ecosystem support, and pilot deployments will determine whether India becomes a technology adopter or a technology leader in the sodium-ion era.

Related articles:

• Battery Energy Storage Systems (BESS)
• Vanadium Redox Flow Battery (VRFB) system