Energy storage device with reduced temperature variability between cells

#The present disclosure relates generally to energy storage devices, and more particularly to an energy storage device having reduced temperature variability between cells inside the energy storage device.

#Typically, for an off-grid or weak-grid consuming entity, e.g. a telecom facility, the main power source may include a hybrid engine-generator/battery system that can be used in backup situations. For example, if power from the commercial utility is lost, the engine-generator set can be activated to supply power to the facility. Start-up of the engine-generator set, however, takes time; therefore, the battery can provide power during this transitional time period. If the engine-generator set fails to start (e.g., runs out of fuel, suffers a mechanical failure, etc.), then the battery is able to provide power for an additional period of time. In this way, electrical energy production does not have to be drastically scaled up and down to meet momentary consumption. Rather, production can be maintained at a more constant level. Thus, electrical power systems can be more efficiently and easily operated at constant production levels.

#Other battery applications may include a grid-connected energy storage system and/or motive-based storage. For example, such grid-connected battery systems can be utilized for peak shaving for commercial/industrial plants, buffering peak loads in distribution grids, energy trading, buffering solar power for night time, upgrade of solar/wind power generation, and/or any other suitable application.

#A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

#FIG. 1 illustrates a schematic diagram of one embodiment of a hybrid power system utilizing one or more energy storage devices according to the present disclosure;

#FIG. 2 illustrates a perspective view of one embodiment of an energy storage device having reduced temperature variability between cells according to the present disclosure;

#Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

#Generally, the present disclosure is directed to an energy storage device having reduced temperature variability between cells of a cell pack. Thus, the present disclosure can be utilized in any suitable battery application, including but not limited to a consuming entity, a grid-connected energy storage system, and/or motive-based storage. In various embodiments, the energy storage device includes an inner housing configured within an outer housing. The inner housing has one or more side walls that define an internal volume. The side walls include, at least, a bottom side wall and a front side wall, with the front side wall having an air inlet and an air outlet configured to circulate cooling air through the energy storage device. The energy storage device also includes a cell pack having a plurality of cells arranged in a matrix within the internal volume of the inner housing atop the bottom side wall. Further, the plurality of sodium nickel chloride cells defines a top surface. In addition, the energy storage device includes at least one thermal spreader plate positioned on the top surface of the cell pack and/or between the cells. Thus, the thermal spreader plate(s) is configured to reduce temperature variability between the cells. In addition, the energy storage device includes a sealed airflow distribution network that circulates airflow without cooling the cells so as to reduce temperature variability across the cells when external air is provided through the air inlet.

#The present disclosure has many advantages not present in the prior art. For example, lowering the temperature gradient across the cell pack allows the cooling air blower to be run longer, which allows the pack to be cooled faster during recharge. Such faster recharge allows customers to get more energy throughput from the battery. In addition, cooling during discharge can provide longer run time for the battery by reducing the peak temperature. Further, a lower temperature also slows cell degradation and thus improves battery life.