Advancements in Sodium Batteries for Sustainable Grid-Storage and Electric Vehicle Applications

Sodium Batteries for Grid-Storage Systems and Electric Vehicles

The future of sodium-ion batteries presents a significant opportunity as a sustainable and cost-effective alternative to conventional lithium-ion batteries, addressing key challenges in energy storage, lithium scarcity, and sustainability. A primary advantage of sodium-ion technology lies in its reliance on soda ash, a readily available material derived from trona, a common mineral in the Earth’s crust. This abundance of soda ash not only reduces material costs but also alleviates ethical concerns and supply chain bottlenecks typically associated with lithium.

Utilizing soda ash as the main source of sodium offers distinct benefits for sodium-ion batteries, particularly in applications involving plug-in electric vehicles (PEVs) and grid storage. In addition to being cost-effective, sourcing sodium from soda ash promotes environmentally friendly practices that bypass the energy-intensive processes linked to lithium mining. Ongoing innovations in sodium battery technology are further enhancing both sustainability and performance.

Advancements in anode and cathode materials—such as advanced carbon anodes and layered oxide cathodes—have led to improvements in energy density, cycle life, and recyclability. Researchers are also making progress in stabilizing electrolytes, boosting efficiency and safety. These developments position sodium-ion batteries closer to competing with lithium-ion systems in terms of energy storage capacity and operational lifespan. However, sodium-ion batteries are especially advantageous for stationary energy storage systems, like those used for solar and wind energy, where their lower cost and scalability shine.

Despite these advancements, sodium-ion batteries still face challenges, particularly in energy density, which limits their applicability in weight-sensitive contexts such as long-range electric vehicles. Nevertheless, their potential for large-scale energy storage makes them a crucial component of a sustainable energy future.

Introduction

The increasing demand for efficient and sustainable energy sources has brought rechargeable batteries to the forefront of technological innovation. Among these, lithium-ion batteries dominate the market for energy supply in smartphones and electric vehicles. The impact of electric vehicles (EVs) on carbon emissions is particularly significant, as 44% of greenhouse gas emissions from the transport sector originate from passenger vehicles (Sheldon, 2023). The adoption of PEVs powered by lithium-ion batteries could greatly reduce carbon emissions, providing a strong environmental incentive for automotive companies to transition from gasoline to electric power.

Since their commercial introduction in the 1990s, lithium batteries have transformed energy storage in portable devices (Li, 2018) and have become the industry standard. However, concerns regarding lithium resource scarcity, long-term sustainability, and rising costs have stimulated extensive research into alternative technologies. These alternatives not only address resource scarcity but also align with global efforts to minimize carbon footprints and promote a circular economy.

Sodium batteries have emerged as a viable alternative to lithium-ion batteries due to the abundance and low cost of soda ash. However, their development is hindered by challenges in achieving competitive energy densities and ensuring long-term stability. This review aims to explore the potential of sodium-ion batteries, contributing to the growing body of research focused on creating efficient, cost-effective, and sustainable energy storage solutions for a rapidly evolving world.

Background

A battery is commonly understood as a voltaic cell composed of an anode, cathode, and electrolyte. These cells operate on an electrochemical reaction, where oxidation occurs at the anode while electrons flow toward the cathode, where reduction takes place. Modern batteries function through a three-step electrochemical reaction. In lithium-ion batteries, lithium-intercalated graphite is split into lithium ions, graphite, and free electrons. The lithium ions and free electrons then combine with cobalt(IV) oxide at the anode to form lithium-cobalt oxide. This dynamic equilibrium enables lithium-ion batteries to be rechargeable (Takada, 2003). While graphite can be replaced with alternative materials like silicon (Zuo, 2017), the fundamental recharging process remains unchanged.

Sodium batteries operate similarly to lithium-ion batteries, with the primary distinction being the substitution of lithium ions with sodium ions. The socio-environmental implications of lithium-ion batteries are significant, as the depletion of lithium cells raises concerns about harmful elements that require proper regulation. The life cycle of lithium-ion batteries, which involves mining raw lithium and managing waste from depleted cells, carries substantial socio-environmental costs (Dai, 2019). The majority of the world’s lithium is extracted from the “lithium triangle” encompassing Chile, Argentina, and Bolivia, often from lands belonging to indigenous communities, raising ethical concerns (Murguía, 2024).

As a nonrenewable resource, lithium’s increasing consumption—180,000 tons in 2022, a 22% increase from the previous year (U.S. Geological Survey, 2024)—highlights the urgent need for alternatives. The complexity of the lithium supply chain leads to bottlenecks that drive up costs (Olivetti, 2017). Recycling efforts for lithium batteries are minimal, with less than 1% of lithium currently recycled (Swain, 2017).

Safety Issues with Lithium-Ion Batteries

While lithium-ion batteries are highly efficient, they pose safety risks, including overheating, short-circuiting, and explosion, particularly when damaged or improperly constructed. The Samsung Galaxy Note 7 recall in 2017 brought significant media attention to these safety issues due to internal short circuits and incorrect electrode lengths (Lan, 2023). The U.S. Consumer Product Safety Commission reported 25,000 incidents involving defective lithium-ion batteries. The phenomenon known as thermal runaway, where batteries heat uncontrollably, can lead to catastrophic failures (Shahid, 2022).

Sodium-ion batteries, while not free from safety concerns, tend to have lower energy density, which reduces the likelihood of severe incidents associated with thermal runaway (Li, 2025).

Factors Affecting Battery Life

Even with ideal care, all batteries experience gradual efficiency loss due to chemical alterations during recharging—a process referred to as battery degradation (Edge, 2021). The formation of a solid electrolyte interphase (SEI) can mitigate degradation by protecting the electrolyte and reducing damage to the electrode (Peled, 2017). However, once a battery is fully depleted, only its casing, electrodes, and a spent electrolyte solution remain.

Sodium Battery Design

Sodium batteries function similarly to lithium-ion batteries, featuring an anode, cathode, and electrolyte with sodium ions serving the role of the anode. In sodium cells, reactions often involve diatomic oxygen and sodium ions to produce sodium peroxide (Song, 2017). Comparisons between sodium peroxide (Na2O2) and lithium peroxide (Li2O2) reveal that sodium peroxide has roughly half the energy density of its lithium counterpart. Lithium’s superior conductivity and higher cell voltage further emphasize the differences between the two (Song, 2017).

Benefits of Sodium-Based Batteries

Research into ion batteries has historically prioritized lithium due to its superior energy density. However, with the rising costs and scarcity of lithium, interest in sodium as a substitute has surged (Delmas, 2018). Sodium is significantly more abundant than lithium, being 1,180 times more concentrated in the Earth’s crust (CRC Handbook of Chemistry and Physics, 2022-2023). This abundance not only makes sodium more accessible for battery production but also contributes to a lower cost—$150 per ton for sodium compared to $37,000 per ton for lithium carbonate as of 2023 (Mineral Commodity Summaries, 2023).

Existing infrastructure for lithium battery production can be adapted for sodium battery manufacturing, making large-scale production feasible without significant investment. With the anticipated increase in sodium battery demand, research is focused on optimizing cell design and enhancing sustainability.

Challenges of Sodium Batteries

Despite their advantages, sodium batteries face challenges related to sustainability and lifespan. Researchers are working to extend the life of sodium batteries by optimizing electrode materials and design (Tapia-Ruiz et al., 2021). One hurdle is stabilizing the interface between the electrode and electrolyte, which is more complicated for sodium than for lithium, resulting in shorter life cycles for sodium batteries (Darwiche, 2016). Fortunately, much of the innovation seen in lithium batteries can inform sodium battery design due to their structural similarities.

Battery Disposal

The disposal of battery waste presents an ecological challenge. Direct recycling, where anode and cathode materials are physically separated and reused, alongside pyrometallurgical or hydrometallurgical methods, are potential solutions for sustainable battery recycling (Bird, 2022). However, the absence of legislative incentives for recycling has led to minimal efforts by corporations. Reducing reliance on polymeric binders, which complicate recycling, is one approach researchers are exploring to enhance recyclability (Tapia-Ruiz et al., 2021).

Thermal Variance

While lithium-ion batteries experience performance losses at low temperatures and aging at high temperatures, similar issues in sodium-ion batteries are less understood (Velumani, 2022). The performance drop at lower temperatures primarily stems from the liquid electrolytes used in sodium batteries, which have high freezing points (Zhang, 2024). Research is ongoing to develop organic liquid electrolytes that can enhance performance across a broader temperature range.

Overview of Sodium-Ion Battery Research

Sodium-ion batteries are emerging as a “drop-in” solution, capable of integrating into existing infrastructure with minimal initial investment. Companies like CATL are already investing in sodium-based cells for use in electric vehicles, while sodium-ion batteries are also being explored for grid storage applications (Chen, 2020). Given their environmental abundance and competitive energy storage capacity, sodium-ion batteries can effectively replace lithium-ion systems in certain large-scale deployments.

Research into Anode and Cathode Selection

The search for suitable anodes for sodium batteries has led to the use of hard carbon, which is effective due to the tendency of sodium ions to fill disordered carbon layers. Transition-metal oxides, particularly titanium-based anodes, are also being researched for their low cost (Zhao, 2017). Innovations in anodes made from biomass, such as olive shell-derived hard carbon, show promise for sustainable applications (Zhou, 2025).

Recent breakthroughs include “anode-free” cells, which eliminate the need for a solid electrode, enhancing energy density by allowing more space for cathode materials (Zhao, 2023). Research into cathode materials has focused on sodium-layered transition metal oxides, with ongoing improvements in their stability and performance helping to boost sodium battery competitiveness.

The Future of Sodium Batteries

The demand for sodium-ion batteries is increasing, with manufacturers like Faradion receiving large orders to meet environmental targets (Faradion, 2020). As sodium and lithium batteries share similar production processes, existing lithium battery factories can transition to sodium battery manufacturing with minimal investment. However, due to lithium’s superior energy density, sodium batteries are likely to remain a secondary option, primarily suited for large-scale applications such as grid storage.

Interest in sodium-ion batteries continues to grow, with projections estimating a market value of $838.5 million by 2029, reflecting a compound annual growth rate of 18.6% from 2024 to 2029 (Arora, 2024). This trend aligns with the increasing discourse around lithium scarcity, highlighting the importance of sodium batteries as a solution for future energy storage needs.

Conclusion

The future of sodium-ion batteries holds significant promise as a sustainable alternative to traditional lithium-ion systems. Their reliance on abundant sodium, as opposed to geographically concentrated lithium, could mitigate costs and geopolitical tensions, fostering equitable energy solutions. Sodium-ion batteries have the potential to transform energy storage, particularly in applications like medium-sized PEVs and grid storage, where their low cost and abundance can be fully leveraged.

Innovations in battery design, including improvements in anode and cathode materials, are enhancing the sustainability and performance of sodium batteries. Ongoing research aims to address challenges such as lower energy density and recyclability, ultimately positioning sodium batteries as complementary to lithium-ion systems in a cleaner, more inclusive energy future.

Authors
Dr. Raj Shah is a Director at Koehler Instrument Company, NY. He holds numerous fellowships and has co-edited the bestseller “Fuels and Lubricants Handbook.”
Dr. Vikram Mittal is an Associate Professor at the U.S. Military Academy, with expertise in energy modeling and alternative fuels.
Mr. Mathew Roshan is an intern at Koehler Instrument Company and a Chemical Engineering student at Stony Brook University.