Nadion Energy

safety advantages of transporting over-discharged sodium-ion batteries

The Safety Advantages of Transporting Over-Discharged Sodium-Ion Batteries

The field of battery technology has seen significant advancements in recent years, driven by the growing demand for energy storage solutions in various applications, including electric vehicles, renewable energy integration, and portable electronics. Among the diverse range of battery chemistries, lithium-ion batteries have dominated the market due to their high energy density and relatively long cycle life. However, emerging technologies like sodium-ion batteries are gaining attention for their potential to complement or even replace lithium-ion batteries in specific applications. We will explore the safety advantages of transporting over-discharged sodium-ion batteries at 0V and how they differ from lithium-ion batteries in terms of cathode and anode materials.

1. Lithium-Ion Batteries: An Overview

Lithium-ion batteries are widely used in today’s technology-driven world, owing to their high energy density, lightweight design, and rechargeable nature. These batteries consist of various components, including a cathode, an anode, an electrolyte, and a separator. The choice of materials for the cathode and anode collectors plays a crucial role in the performance and safety of lithium-ion batteries.

In lithium-ion batteries, aluminum foil is commonly employed as the cathode collector, while copper foil is used for the anode collector. This selection is based on the respective potentials of these materials within the battery. The cathode typically operates at a higher potential, making aluminum foil an ideal choice due to its high oxidation potential and the presence of a dense oxide film on its surface. This oxide film provides internal protection and helps maintain electrochemical stability within the positive potential range of the lithium-ion battery. Additionally, aluminum has a low embedded lithium capacity, which makes it suitable for use as a cathode collector.

However, aluminum cannot serve as a collector for lithium-ion battery anodes. This limitation arises from the similarity in the lattice octahedral gap size of aluminum metal to that of lithium, facilitating the formation of metal gap compounds with lithium. These compounds take the form of alloys with chemical formulas such as LiAl, Li3Al2, or Li4Al3.

2. The Challenge of Alloys in Lithium-Ion Battery Anodes

The formation of alloys between lithium and aluminum is a significant concern when using aluminum foils as anodes in lithium-ion batteries. This alloying reaction consumes a considerable amount of lithium and compromises the structural and morphological integrity of the aluminum foil. As a result, lithium and aluminum are better suited as anode collectors for lithium-ion batteries.

Conversely, copper foil, which is used as the anode collector, has a porous oxide layer. This porous nature prevents oxidation and ensures consistent electrochemical performance. Lithium struggles to form a lithium-copper alloy at low potential, making copper foil an outstanding option for a lithium-ion battery anode collector, given its structural soundness.

3. Over-Discharge Risk in Lithium-Ion Batteries

While copper foil is a suitable choice for the anode collector in lithium-ion batteries, there is a potential risk associated with over-discharged batteries. Over-discharging can lead to an increase in the anode’s potential, which, in turn, triggers the oxidation and dissolution of the copper foil. The dissolved copper factors undergo an initial oxidation process to Cu+ and later precipitate and deposit on the copper metal dendrite surface. This process can puncture the separator, leading to a short circuit between the positive and negative electrodes, ultimately resulting in the complete failure of the battery.

Nadion EneSodium-ion Batteries

4. Sodium-Ion Batteries: A Safer Alternative

Sodium-ion batteries have emerged as a potential alternative to lithium-ion batteries, offering certain advantages, particularly in terms of safety during over-discharge conditions. In sodium-ion batteries, aluminum foils can be used for both the cathode and anode collectors. This choice eliminates the need for comparatively costly copper foils with low oxidation potential and brings inherent safety benefits.

In sodium-ion batteries, the anode is also made of aluminum foil, which contributes to the safety characteristic of being able to over-discharge at 0V. When sodium-ion batteries are fully discharged to 0V, the cathode reaches a lower potential while the anode reaches a higher potential, typically between 2~3V. Importantly, unlike lithium-ion batteries, there is no need to worry about the oxidation and dissolution of the copper foil in sodium-ion batteries, as aluminum remains stable at this potential range.

5. Safety Implications of 0V Over-Discharge

The ability of sodium-ion batteries to be fully discharged to 0V without a notable effect on their electrochemical performance enhances their safety during storage and transportation. This feature has significant implications for the industry, particularly in scenarios where batteries may be subjected to extended periods of disuse or storage at low charge states.

One of the primary safety concerns with lithium-ion batteries is the risk of thermal runaway and cell rupture when they are over-discharged or exposed to unfavorable conditions. In contrast, sodium-ion batteries offer a more stable and robust solution for applications where prolonged storage or transportation at 0V is required.

6. Applications and Industry Considerations

The safety advantages of sodium-ion batteries during over-discharge conditions open up opportunities for their use in a wide range of applications. Here are some key areas where sodium-ion batteries could find applications due to their ability to safely operate at 0V:

6.1 Energy Storage Systems (ESS)

Sodium-ion batteries could serve as a reliable energy storage solution for grid-level ESS, where safety and long-term performance are paramount. Their ability to withstand over-discharge without compromising safety makes them an attractive choice for utility-scale energy storage.

6.2 Remote and Off-Grid Locations

In remote or off-grid locations where power supply interruptions are common, sodium-ion batteries could provide a dependable backup power source. The ability to store energy for extended periods without risk makes them suitable for such applications.

6.3 Transportation

Electric vehicles (EVs) and electric bikes powered by sodium-ion batteries could benefit from the safety of 0V over-discharge. This could lead to increased consumer confidence in EVs and potentially reduce the risk of battery-related incidents.

6.4 Aerospace

Sodium-ion batteries may find use in aerospace applications where extended periods of inactivity and low charge states are common. Their safety profile aligns with the stringent requirements of aerospace industries.

6.5 Medical Devices

Medical devices that rely on battery power, such as implantable medical devices and portable medical equipment, could benefit from sodium-ion batteries’ safety features, ensuring reliable performance over time.


The safety of transporting over-discharged sodium-ion batteries at 0V presents a significant advantage over lithium-ion batteries, especially in scenarios where batteries may experience extended periods of inactivity or low charge states. The choice of aluminum foil as both the cathode and anode collector in sodium-ion batteries eliminates concerns related to oxidation and dissolution, making them a promising technology for various applications, including energy storage, transportation, aerospace, and medical devices.

As the demand for energy storage solutions continues to grow, sodium-ion batteries are poised to play a vital role in addressing the safety and performance requirements of different industries. However, it is essential to note that while sodium-ion batteries offer distinct advantages, their commercialization and widespread adoption will depend on further research and development efforts to optimize their performance, cost-effectiveness, and scalability in comparison to other battery technologies.

For more information, please visit Nadion Energy.

Leave a Comment

Your email address will not be published. Required fields are marked *