Vehicles using electric power for all or a portion of their motive power may provide a number of advantages as compared to more traditional gas-powered vehicles using internal combustion engines. For example, vehicles using electric power may produce fewer undesirable emission products and may exhibit greater fuel efficiency as compared to vehicles using internal combustion engines (and, in some cases, such vehicles may eliminate the use of gasoline entirely).
As technology continues to evolve, there is a need to provide improved power sources (e.g., battery systems or modules) for such vehicles. For example, it is desirable to increase the distance that such vehicles may travel without the need to recharge the batteries. It is also desirable to improve the performance of such batteries and to reduce the cost associated with the battery systems.
One area of improvement that continues to develop is in the area of battery chemistry. Early systems for vehicles using electric power employed nickel-metal-hydride (NiMH) batteries as a propulsion source. Over time, different additives and modifications have improved the performance, reliability, and utility of NiMH batteries.
More recently, manufacturers have begun to develop lithium-ion batteries that may be used in vehicles using electric power. There are several advantages associated with using lithium-ion batteries for vehicle applications. For example, lithium-ion batteries have a higher charge density and specific power than NiMH batteries. Stated another way, lithium-ion batteries may be smaller than NiMH batteries while storing the same amount of charge, which may allow for weight and space savings in a vehicle using electric power (or, alternatively, this feature may allow manufacturers to provide a greater amount of power for the vehicle using electric power without increasing the weight of the vehicle using electric power or the space taken up by the battery system).
It is generally known that lithium-ion batteries perform differently than NiMH batteries and may present design and engineering challenges that differ from those presented with NiMH battery technology. For example, lithium-ion batteries may be more susceptible to variations in battery temperature than comparable NiMH batteries, and thus systems may be used to regulate the temperatures of the lithium-ion batteries during vehicle operation. The manufacture of lithium-ion batteries also presents challenges unique to this battery chemistry, and new methods and systems are being developed to address such challenges.
It is also generally known that batteries and battery systems (both lithium-ion and NiMH) are subjected to various environmental and other potentially damaging conditions. For example, battery systems are sometimes provided on the exterior or underside of a vehicle using electric power, subjecting the battery systems to rain, snow, sleet and any other combination of inclement weather. Such battery systems may also be impacted by an object, such as, e.g., during an accident, which may cause a short circuit condition of the battery. Further, abuse of a battery (e.g., a short circuit, or over/under charging) may lead to high temperatures and/or excess pressure within the battery, causing the battery to vent electrolyte contained within the battery.
It would be desirable to provide an improved battery module and/or system for use in vehicles using electric power that addresses one or more challenges associated with NiMH and/or lithium-ion battery systems used in such vehicles. It also would be desirable to provide a battery module and/or system that includes any one or more of the advantageous features that will be apparent from a review of the present disclosure.