Lithium-ion batteries have been the go-to choice for energy storage in a wide range of applications, from portable electronics to electric vehicles. However, lithium is a relatively scarce resource, and its price has been volatile in recent years. This has led to a growing interest in alternative battery chemistries, one of which is on the horizon, namely, sodium-ion batteries.
Sodium-ion batteries (also called Na-ion batteries or NIB) work in a similar way to lithium-ion batteries, but they use sodium ions instead of lithium ions. Sodium is much more abundant than lithium, and it is also cheaper. This makes sodium-ion batteries a potentially more sustainable and affordable option.
These batteries are gaining traction due to their abundance, affordability, and potential for various applications. In this article, we'll explore what sodium-ion batteries are, their advantages and disadvantages, and their potential impact on the energy storage landscape, with a special focus on Biwatt's latest offering.
How Sodium-ion Batteries Work
Similar to their lithium-ion counterparts, sodium-ion batteries operate on a basic principle of chemical reactions. The choice of materials for these electrodes and electrolytes plays a crucial role in determining the battery's performance and lifespan. In the case of NIBs, they consist of two electrodes, one positive and one negative, separated by an electrolyte that enables the flow of sodium ions.
Advantages of Sodium-ion Batteries
Abundance
Sodium is considerably more abundant than lithium, making it a cost-effective and sustainable choice for battery production.
Cost
Sodium-ion batteries are potentially less expensive to manufacture than lithium-ion batteries because sodium is a much more abundant and less expensive element than lithium.
Sustainability
Sodium-ion batteries are more environmentally friendly than lithium-ion batteries because sodium is a less toxic element than lithium. Also, they do not rely on scarce materials like cobalt and nickel, which are commonly used in lithium-ion batteries.
Safety
Sodium-ion batteries are generally considered to be safer than lithium-ion batteries because they are less prone to overheating and catching fire.
Charge/Discharge Cycles
Recent developments have shown that sodium-ion batteries can achieve a high number of charge/discharge cycles, indicating durability and longevity.
Low-Temperature Performance
Sodium-ion batteries perform well in low-temperature conditions, addressing a common challenge faced by lithium-ion batteries.
Disadvantages of Sodium-ion Batteries
Energy density
Sodium-ion batteries currently have a lower energy density than lithium-ion batteries, which means that they cannot store as much energy in the same volume.
Power density
Sodium-ion batteries also have a lower power density than lithium-ion batteries, which means that they cannot deliver as much power in the same amount of time.
Cycle life
Sodium-ion batteries currently have a shorter cycle life than lithium-ion batteries, which means that they will need to be replaced sooner.
Commercialization Efforts
British company, Faradion is regarded as the pioneer of sodium-ion batteries. It was later bought-out by Indian conglomerate, Reliance Industries. Several companies, including HiNa and Chinese state-owned China Three Gorges Corporation, have already started mass production of sodium-ion batteries. The first-generation sodium-ion batteries offer a decent energy density, and more importantly, they boast an impressive lifespan of around 4,500 charge cycles.
The electric vehicle industry where lithium is king, is slowly being disrupted by sodium-ion. In June 10, 2023, the world's second largest manufacturers of electric vehicles, BYD and Huaihai Holding Group have announced a partnership to become world leaders in producing sodium-ion batteries for small EVs. According to the partnership, the companies would aim to “jointly create the world’s largest supplier of sodium battery systems for micro vehicles.”
The Case of Biwatt
Chinese manufacturer Biwatt Power has been at the forefront of sodium-ion battery innovation. Their latest offering, the I.Power Nest solution, is a game-changer in the residential energy storage sector. Measuring 600 mm x 810 mm x 155 mm and weighing 60 kg, these batteries offer an impressive efficiency rate of 97% and an expected lifespan of more than 3,000 cycles. The batteries are also IP21 rated and feature a cooling system based on forced air.
The Biwatt I.Power Nest NIBS are designed for use in residential energy storage systems. They can be used to store excess solar energy and then release it when needed, to provide backup power during outages, or to reduce electricity bills by charging during off-peak hours and discharging during peak hours.
Key Highlights of Biwatt's I.Power Nest:
Efficiency: 97%
Expected Lifespan: >3,000 cycles
Cell Capacity: 75 Ah
Rated Battery Voltage: 48 V
Maximum DC Power: 6 kW
Maximum Input Voltage: 500 V
MPPT Voltage Range: 120 V to 450 V
Maximum MPPT Input Current: 13 A
Enclosure: IP21
Cooling System: Forced air
An intelligent app accompanies Biwatt's I.Power Nest, allowing users to effortlessly control home electricity usage and switch between various operating modes. This innovation makes electricity usage more convenient and worry-free for homeowners.
What the Future Holds
Researchers worldwide are actively working on improving sodium-ion battery technology. Areas of focus include enhancing energy density, voltage, lifespan, and charge/discharge rates. If these efforts prove successful, sodium-ion batteries could become a viable alternative for a wide range of applications, including portable electronics, electric vehicles, and stationary energy storage systems. BloombergNEF recently updated its technology outlook to include sodium-ion batteries saying they could play a “meaningful role” in the energy storage industry by 2030.
Conclusion
Sodium-ion batteries are a promising new battery technology with the potential to address many of the limitations of lithium-ion batteries. However, they are still in their early stages of development, and more research is needed to improve their performance and commercial viability.
The new sodium-ion offering by Biwatt is a significant development in this market. The batteries offer a number of advantages over lithium-ion batteries, and they are well-suited for use in residential energy storage systems. It will be interesting to see how the Biwatt sodium-ion batteries are received by the market, and whether they can help to accelerate the adoption of sodium-ion battery technology.