The vast majority, upwards of 80% in recent years, of energy storage installations have used lithium-ion batteries. Lithium-based deployments have continued apace despite supply chain concerns, largely because of lithium batteries’ falling prices and exceptional efficiency.
Lithium’s dominance, however, has led to concerns about its continued ability to meet the expected demand for energy storage and its safety risks. This has, in turn, opened the door for alternative battery formulations. One of the most promising technologies to emerge is sodium-ion batteries. After years of familiarity with lithium, battery operators may have reservations about adopting a new technology. Still, with the right software tools, sodium-ion may prove to be just as good a fit as lithium.
Sodium-ion and the race for lithium alternatives
While lithium has stabilized since the most severe supply chain disruptions of the COVID-19 pandemic, the same issues remain. Most of the industry’s lithium comes from only a few countries; in the United States, only one active lithium mine exists. This could be problematic for what’s expected to be several years of protectionist trade policies. Between the growth in EVs, battery storage, and the need for lithium in a myriad of other applications, there are also concerns about whether global lithium production can meet demand in the years ahead. For a product that is driving the clean energy transition, lithium extraction is also quite resource-intensive and damaging to the environment.
Outside of sourcing, there are other issues with lithium batteries. Their composition depends on critical minerals like cobalt, nickel, and copper. Copper is used as the current collector at the negative electrode.
There are also safety concerns around lithium batteries, such as thermal runaways that have occurred more frequently as installations have increased. Additionally, there’s the risk of being over-reliant on a single chemistry for an application expected to ramp up tremendously in the years ahead.
Figure 1. Abundance of raw materials in Earth’s crust (Image: Billy Wu)
These worries underscore the excitement for alternatives to lithium batteries. Sodium-ion batteries are technically similar to lithium-ion batteries in how they charge and discharge, yet they offer comparable or better performance while tackling several of lithium’s limitations. As the name suggests, sodium-ion batteries use sodium. Sodium is far more abundant, up to 1000 times more abundant than lithium (Figure 1). It is also a more cost-effective resource than lithium.
Today, sodium-ion batteries have a wide variety of material compositions, much like in lithium-ion technology. These material choices define cell performance, cost, lifetime, and safety. Sodium-ion batteries already feature several categories of anode and cathode materials. Anode materials include carbonaceous materials, alloy, and metal oxides/sulfides. Cathode materials encompass layered metal oxides, polyanion compounds, and Prussian blue analogues. Unlike lithium-ion batteries, where established chemistry categories such as lithium-iron-phosphate (LFP), nickel-manganese-cobalt (NMC), and nickel-cobalt-aluminum (NCA) exist, there are no standardized chemistry classifications for sodium-ion batteries yet. However, industry standards will emerge as technology matures, bringing greater consistency and predictability to sodium-ion battery development.
Moreover, the mass production of sodium-ion energy storage does not face supply chain constraints and is also far less environmentally damaging to extract. While sodium-ion batteries may not reach the upper threshold of lithium, they can be operated with a reduced risk of thermal runaway and less stringent handling requirements. Table 1 shows a high-level comparison between sodium-ion and lithium-ion technologies.
Table 1. Sodium-ion Vs. Lithium-ion batteries. (Image: World Sustainability Collective)
These benefits mean sodium-ion has a good chance of being one of the more successful lithium alternatives, particularly as operators can deploy it for similar energy storage applications. However, the technology is still in its infancy, and while pilot projects have demonstrated exciting potential, the first commercial sodium-ion batteries only entered production in 2024. This leaves time for developers to determine how best to deploy sodium-ion batteries.
Figure 2 presents market demand projections for lithium and sodium-ion batteries across various applications by 2030. Sodium-ion battery systems are expected to reach a total capacity of 394 GWh, accounting for 8% of the total battery market. For energy storage system (ESS) applications, sodium-ion batteries are projected to cover 34% of the market, with a total demand of 290 GWh.
Figure 2. Market demand for Li-ion and Na-ion batteries by application. (Image: “Na-ion Batteries: Materials and State of the Art”, Advanced Automotive Battery Conference [AABC])
Using modeling to prepare for a sodium-ion future
As system operators and developers can attest, battery simulation models have already proven to be a game-changer for storage applications. Battery storage systems are a complex and, at times, demanding technology, often performing in unexpected ways or degrading faster than designed. Models that can simulate usage scenarios have successfully detected and signal issues in lithium-ion batteries. Operators today rely on simulation models to predict how batteries will perform and age in specific use cases, receiving guidance on how best to deploy storage systems. Beyond the basic energy management software with battery storage, simulation models help operators avoid issues before they occur and wring the most performance out of their systems.
With lithium-ion being such an established technology, simulation models are especially well-suited for lithium batteries. Now, thanks to the work of a select few cleantech firms, operators can begin using these same proven models to simulate how sodium-ion batteries will perform. The simulation models will enable technicians to learn more about how sodium-ion operates before the batteries become widely available commercially, giving operators a tool to familiarize themselves with sodium while planning for their potential deployment.
As with lithium-ion modeling, simulating the behavior of sodium-ion batteries reveals a wealth of extensive technical information for operators. The models can measure and analyze factors like a battery cell’s voltage, state-of-charge, open-circuit voltage, and temperature, considering them all when anticipating how a sodium-ion battery will operate under the prescribed conditions. The models also allow operators to evaluate how sodium-ion cells will degrade compared to lithium, providing further information on whether to deploy them.
For storage operations, optimizing battery performance while minimizing degradation is crucial. The faster battery storage ages, the less revenue it can make. Simulation models help evaluate how the battery ages in different scenarios like arbitrage, frequency containment reserve, and peak shaving. The models can also provide a detailed assessment of different operational strategies: What is the ideal state of charge for resting periods to minimize battery degradation? How can asset managers fine-tune operational strategies to balance profitability and battery longevity? What are the key factors influencing degradation costs?
Ultimately, simulation models give storage operators a tool for familiarizing themselves with a novel technology. Many technicians are keenly aware of how helpful modeling is for lithium-ion batteries. They can apply those same tools to closely examine one of the most promising lithium alternatives.
