Not every battery maker is a household name. There are many small battery manufacturers who are making advanced batteries to power a variety of electric vehicles from golf carts to heavy-duty trucks. Kokam, for example, a Korean company with manufacturing facilities in the United States, has just announced its new XPAND lithium-ion battery system.
The XPAND system uses lithium-nickel-manganese-cobalt battery cells in two basic sizes — 7.1 kWh or 11.4 kWh. The individual packs can be added together for a total of 1.5 megawatt-hours of battery storage, depending on the needs of the customer. The individual packs are liquid cooled, have a lifespan of 6,000+ discharge cycles, and have a maximum energy density of 150 watt-hours per kilogram.
For comparison purposes, the current batteries in the Tesla Model S and Model X have an energy density of around 135 watt-hours per kilogram — although, the batteries for the upcoming Model 3 are expected to have a higher energy density.
Such large lithium-ion battery packs may not be ideal for passenger cars but could be perfect for powering buses and large trucks. Recently, a consortium of mayors from cities across the United States have asked for proposals for such things as electric fire trucks and trash hauling vehicles.
Kokam uses ceramic separators between the battery cells and other battery pack thermal containment technologies to prevent the thermal runaway that can sometimes cause battery cells to explode or burst into flame. The fully automated battery factory in the United States has an annual capacity of 700 megawatt-hours of batteries. That’s far less than the Tesla Gigafactory at 35 gigawatt-hours, but still a significant amount.
The Kokam batteries have all their external connections on the front panel where they are easily accessible. The modular design means servicing the battery packs in the field is a simple and straightforward process.
The battery management system built into each battery pack is able to accurately report on the state of charge of all cells, which allows drivers and equipment operators to more precisely predict how much power remains. That reduces the likelihood that a vehicle will run out of charge away from the nearest charging equipment.
As vehicles become more modular, batteries, electric motors, and battery management systems from independent suppliers like Kokam will help get more electric vehicles on the road at minimum cost.
Source: Inside EVs