Mechanism

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These types of batteries are composed of a molten sulfur cathode and a liquid sodium anode, which are separated by a solid ceramic material that fulfills the electrolyte function. Only positively charged sodium ions can pass through this electrolyte.

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Capacities and lifecycle

 

Normally units have a nominal power between 50kWh and 400kWh, and their minimum state of charge i 10%, with a performance of 85%. Its lifetime is estimated at 4500 cycles of loading and unloading, which is equivalent to 15 years. Its price is around US $ 320 per kWh and the operation and maintenance cost is around US $ 4 per kWh.

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Applications

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One of the main uses of this battery is to store wind energy.

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Advantages

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Their response time is one millisecond.They are strong and less sensitive; and they can be built in different shapes and sizes. They don’t not use lithium or cobalt, which are elements that are relatively scarce, instead use sodium and sulfur which are abundant elements in nature.

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Disadvantages

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They can only be used in non-mobile applications, which are prone to corrode and form dendrites which increase self-discharge.They require closed cells because sulfur and sodium are flammable when heated in the presence of air and even with a special insulation that minimizes heat loss.These batteries are a high temperature model, they operate at a temperature of 300°C. Because of this, they should be used in systems that produce high temperatures. Heating consumes 14% of the energy if the battery is not used.

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Project: Abu Dhabi integrates the world's largest virtual battery plant.