Solid-State vs Sodium-Ion: Who Will Dethrone Lithium-Ion Batteries?

The rise of renewable energy (RE) and the electric vehicle boom have brought with them increased expectations from the energy storage industry like increased efficiency, considerably high safety, and huge energy densities, and of course preferably at lower costs. Aiming to offer options are Sodium-ion batteries and solid-state batteries. Both have their own sets of advantages, which have the potential to make existing Li-ion storage technology redundant in the years to come, though certainly not significantly for a decade at least.

In this blog, we explore why the lithium ion does face the risk, however small it might seem, of going out of work. We focus on the best current prospects of two emerging technologies – sodium ion and solid state batteries – to take the reins of energy storage.

Dominance of Lithium-ion Batteries

Lithium ion batteries currently dominate the energy storage scene and are expected to remain at the helm for the medium term. From mobile batteries to huge energy + storage RE projects, Li-ion technology is powering all the trends. 

As per a report, the lithium-ion battery materials market is expanding rapidly due to rising demand for lithium-ion batteries across a variety of industries and is expected to grow threefold from USD 41.9 billion in 2024 to over USD 120 billion by 2029, clocking a CAGR of about 23.6 percent. The current lithium-ion battery market is dominated by well-established players, such as Tesla, Panasonic, LG Chem, CATL, and BYD. With the last two from China in particular making giant strides in the past two years. 

The rising adoption of new age technologies like EV is mostly responsible for this increase in demand. Yet, the stationary storage market demands more.

Challenges for Li-ion 

It is well known by now that Li-ion cells rely on critical minerals like lithium and often cobalt and nickel. Supply constraints have led to volatile prices. For instance, battery-grade lithium carbonate costs fluctuated from about USD 5.8 up to USD 80 per kilogram in recent years. Such volatility and scarcity drives up Li-ion battery costs and pose long-term supply risks.

Among the pressing concerns is the lack of a strong lithium supply chain in major markets apart from China. Roughly 77 percent of graphite for lithium-ion batteries comes from China. This highlights the huge dependence in the era of trade wars and the need to diversify supply. Safety risks like EV battery fires due to thermal runaway have further posed problems.

These factors are now paving the way for the new generation of energy storage technologies. Even as non-China players have worked to find options that donot depend on Lithium Ions, Chinese market leaders have also been alive to the risk of any threats to their market dominance, and have in fact been very fast movers in the Sodium Ion or Solid state segments as well in an effort to cover flanks.  

Hyper-Activity in Solid State Battery Industry

A solid-state battery (SSB) uses a solid electrolyte (ceramic, glass, or solid polymer) in place of the liquid​ used in its Lithium-ion counterpart. By eliminating bulky graphite anodes and using dense solid materials, SSBs can pack more energy in the same space, helping in substantially increasing the range of EVs. Some major players in the sector have already acknowledged the technology for its potential.

QuantumScape 2024 prototype solid-state cell (QSE-5) reached an energy density of 844 Wh/L, significantly above typical commercial Li-ion batteries that range between 300–700 Wh/L. Their first commercial 100+ layer cell (QSE-5) is planned for 2025 deliveries​. This volumetric energy, roughly 1.5× higher than the best current Li-ion cells, means a 20–50 percent greater driving range for the same battery weight/volume offered by Lithium-based batteries.

China’s global battery leader Contemporary Amperex Technology Limited (CATL) also increased its R&D investment, expanding its R&D team for the program to over 1,000 people. The Chinese firm is targeting small-volume production of all solid-state batteries in 2027.

Toyota announced a timeline for commercialization in passenger EVs by 2027-2028. Toyota also claimed up to 20 percent greater range from its innovation. Solid Power, in 2023, supplied A-sample cells to BMW for a demo vehicle program​. Other major industry leaders are also venturing the industry with investments by the likes of Volkswagen, Hyundai, Nissan, BMW  and Toyota. 

In addition to greater range, the solid state batteries also exhibit excellent fast-charging capability. Their superior thermal stability and ionic conductivity allow for very high charge rates without damaging the cell. 

For instance, Toyota projects that its solid state battery tech can replenish 300 km range in just 15 minutes. This is roughly 2–3× faster than typical EV fast-charging today, which is about 30 min for 10–80 percent on many lithium-ion EVs.

Solid electrolytes are non-flammable, removing the main risk associated with conventional battery cells. The solid ceramic or glass electrolytes do not ignite, and many can operate at wider temperature ranges. They are also stable at higher voltages, enabling high-capacity new cathode materials, and can suppress lithium dendrite formation, which improves cycle life and safety. 

Furthermore, the solid–state batteries may also prove easier to recycle as they use simpler cell designs – no complex mix of solvents and binders – and can avoid problematic binders and additives. 

What’s Stopping it from Market Takeover?

Considering so many merits, one would think that solid state should replace lithium ion easily and sooner. It would have done so, if not for the high costs. 

It was the high cost of solid state batteries that forced BMW to announce that, despite expecting a demonstrator vehicle with solid-state batteries later this year, the Group is unlikely to launch an EV with solid-state batteries until the next decade.

As per Sunwoda, a Chinese battery maker, the expected solid state battery prices may be marked around USD 275/kWh, close to the cost of semi-solid-state batteries. However, the actual prices may go much higher due to the high material processing costs and low-throughput manufacturing methods currently in use. 

In comparison, the average lithium-based battery pack prices in China touched USD 94/kWh in December 2024. In the US and Europe the price was slightly higher – 30-50 percent higher – still  considerably below a solid state power pack.

Thus, the cost component is a major bottleneck which the promoters of the battery tech need to address before it can disrupt the energy storage market. On this front, sodium-ion and lithium-ion counterparts are way ahead of solid-state.

Other key challenges include scaling up manufacturing that involves producing ceramic electrolytes in large volumes and assembling cells reliably. Managing the interface between solid electrolytes and electrodes which can have higher resistance or form cracks over many cycles is also an issue that is hampering the technology to go fully commercial. Furthermore, ensuring durability under real-world stresses, such as vibration, temperature swings, fast charging, is among the major challenges.

Super Affordability: The Era of Sodium-ion Cells

While solid-state batteries improve upon Li-ion by changing the electrolyte and higher energy density, but trip up on cost, sodium-ion (Na-ion) batteries face the opposite problem. By seeking to replace the very elements used in Li-In batteries with commonly available materials, the batteries could be far lower priced, but face an energy density challenge. These batteries operate on the same basic principle as Li-ion – shuttling ions between cathode and anode – but use sodium ions instead of lithium. 

This changes everything, from ease of raw material procurement to the affordability component, one of the major factors in deciding the dominant battery tech of the future. 

Their low cost means Sodium-ion batteries are set to provide less than 10 percent of EV batteries to 2030 and make up a growing share of the batteries used for energy storage because they use less expensive materials and do not use lithium, resulting in production costs that can be 30 percent less than lithium iron phosphate (LFP) batteries.

The biggest appeal of sodium-ion technology is the use of abundant, inexpensive materials in place of scarce ones. Sodium is 1,000 times more abundant in the Earth’s crust than lithium​. They can potentially even be extracted cheaply from relatively infinite seawater. 

Technology Advancements are Making a Case for Sodium-ion Batteries

Thanks to innovations, today’s commercial-grade Na-ion cells have achieved energy densities of about 130–160 Wh/kg, roughly 2/3 that of typical Li-ion NMC cells, but already rivaling or exceeding lead-acid and approaching LFP batteries. Experts claim they will exceed 200 Wh/kg in the next generation, which actually surpasses the theoretical limit of LFP chemistry.

While typical sodium-ion devices offer a lifespan of 100 to 1,000 cycles, Indian developer KPIT claims to have achieved 80 percent capacity retention over 6,000 cycles, matching lithium-ion performance.

Sodium-ion cells shine in power and low-temperature performance as well, with some designs potent to deliver about 1 kW/kg, much higher power density than Li-ion NMC or LFP cells. In addition, they also experience less degradation in sub-zero temperatures, at –20°C, where Li-ion cells struggle to retain charge or fast-charge efficiently.

Additionally, sodium-ion batteries can be fully discharged to 0 V without harm rendering them safe for transportation and storage. These batteries are also proving to be more thermally stable as they generate less heat internally and many designs use non-combustible materials. In practical terms, a Na-ion battery pack is expected to be significantly less likely to catch fire than a Li-ion pack, enhancing safety for EVs and especially for grid storage.

These parameters are making them an attractive option for even the lithium-ion leader China. Last year, China put the first large-scale sodium-ion battery storage station into operation – a 10-MWh sodium-ion battery storage facility which is the first phase of an overall 100-MWh project. The facility, built by China Southern Power Grid, uses 210 Ah sodium-ion battery cells and boasts some impressive stats – the cells can charge to 90 percent in just 12 minutes.

Proponents of Sodium-ion

CATL, the world’s largest battery maker, is certainly not waiting to find out. For instance, it is integrating sodium ion into its lithium ion infrastructure and products. In 2023, the firm informed that the Chinese automaker Chery would be the first to use its sodium ion batteries. In January 2024, the biggest carmaker of central Asia and the one of the biggest battery suppliers, BYD, said it started construction of a CNY 10 billion (USD 1.4 billion), 30 GWh per year sodium ion battery factory.

The European players are also exploring the tech with now bankrupt battery maker Northvolt unveiling 160 Wh/kg-validated sodium ion battery cells in November 2023. In the UK, Faradion has been a pioneer of sodium-ion for over a decade. Acquired by India’s Reliance Industries in 2021, Faradion developed cells around 160 Wh/kg and is now transferring a new, improved cell design to production with 20 percent higher energy density and 30 percent longer cycle life. 

Reliance has also expressed plans to build a double-digit GWh factory in India for Na-ion batteries, with production lines possibly starting by 2025. 

All these developments make a strong case for Sodium-ion batteries to be the tech competing Li-ion’s hegemony.

Solid State or Na-ion, Which Battery Tech Will Challenge Li-ion Dominance?

While the emerging battery technologies – sodium-ion and solid-state -present a strong case, it is  hard to view the outcome in a monochromatic tone. Considering the individual merits, both the technology may help contribute to the growth of clean energy and clean mobility in the future.

Solid-state batteries may overtake the market in high-performance niches like EVs within a decade if their costs drop, maybe to USD  80-100/kWh from today’s USD 150+ for lithium-ion. This is highly likely. IEA reports optimistically for solid state battery cost beyond 2030, noting that solid-state batteries are on track to be commercially available.

On the other hand, owing to its cost competitiveness, Sodium-ion is more suitable for grid storage and emerging markets and may make a mark sooner with many proponents already pushing for huge projects in the next two to three years. The BESS market expanded by 44 percent in 2024, installing 69 GW/161 GWh of capacity and discharge output. Notably, batteries are expected to drive 90 percent of energy storage growth by 2030 to meet net-zero goals.

So, expect a spectrum of battery technologies powering the future, with solid state and sodium-ion solutions leading the charge.