Sodium sulfur battery is expected to break through the encirclement! The capacity of the new version is 4 times higher than that of lithium battery, with good stability and lower cost

An international team of scientists focusing on next-generation energy storage solutions recently demonstrated an environmentally friendly and low-cost battery with exciting potential. Compared with typical lithium-ion batteries, this new sodium sulfur battery design provides four times the energy capacity, which is a promising technology for energy storage in the future grid scale.

The team's invention essentially belongs to a kind of battery called molten salt battery, which has existed in various forms for about 50 years. With the increasing attention paid to renewable energy, scientists are optimistic about the potential of molten salt battery for energy storage, because the price of molten salt battery is relatively low and it depends on common materials.

In theory, they can be built on a larger scale to store large amounts of renewable energy. Their typical version relies on sodium sulfur chemistry and keeps the electrode at a high temperature to keep the electrolyte in a liquid molten state. Chinese and Australian scientists have jointly developed their own version, which they say has greatly improved performance at room temperature.

Dr. Shenlong Zhao, the chief researcher of the University of Sydney, said, "When the sun is not bright and the breeze is not blowing, we need high-quality energy storage solutions, which do not consume the earth's resources and are easy to obtain at the local or regional level. We hope that by providing a technology to reduce costs, we can reach the level of clean energy faster."

Therefore, the research team started to solve several shortcomings of sodium sulfur batteries at present. These shortcomings are related to their short life cycle and limited capacity, which hinder their practicability in commercial applications. The team's design uses carbon based electrodes and a thermal degradation process called pyrolysis to change the reaction between sulfur and sodium.

As a result, this new sodium sulfur battery has a high capacity of 1017mAh g − 1 at room temperature. The team pointed out that this is about four times the capacity of lithium ion batteries. Importantly, the battery has also shown good stability and can still maintain about half of its capacity after 1000 cycles, which is described as "unprecedented" in the team's paper.

Shenlong Zhao pointed out, "Our sodium battery has the potential to significantly reduce costs, while providing four times the storage capacity. This is a major breakthrough in the development of renewable energy." This research result has been published in the journal Advanced Materials recently.