Chemistry Igcse- Batteries
BATTERIES
What is a battery?
A battery is a container consisting of one or more cells carrying an electric charge and used as a source of power.
SECONDARY BATTERIES * rechargeable * high cost (short-term) low cost (long-term) * used in objects with high energy requirements:
e.g. mobile phones, power tools * require special handling, containment & disposal
* limited interchangeability * long life time * produce smaller amount of waste (flat discharge curve) * high energy efficiency * used in situations where charging is practical
* lower energy density: part of battery space used in design to accommodate re-charging * lower initial voltage * may not always be readily operational, must be charged * low internal resistance * Materials used: * nickel-metal-hydride (NiMH) * high specific energy * fewer toxic metals than (NiCd) * used in medical instruments * lithium-manganese (LiMN2O4) * high charge & discharge current * low specific energy * short-medium length service life * used in power tools
Batteries are divided into two categories:
PRIMARY BATTERIES * non-rechargeable * low cost (short-term) high cost (long-term) * used in objects with low energy requirements:
e.g. hearing aids, watches, remote controls * do not require special handling, containment & disposal * higher level of interchangeability * short life time * produce larger amount of waste (sloping discharge curve) * low energy efficiency * used in situations where recharging is impractical:
e.g. forest-fire services * higher energy density
* higher initial voltage * readily operational
* high internal resistance * Materials used: * lithium iron disulfide (Li-FeS2) * high capacity * low internal resistance * low performance
What is a battery?
A battery is a container consisting of one or more cells carrying an electric charge and used as a source of power.
SECONDARY BATTERIES * rechargeable * high cost (short-term) low cost (long-term) * used in objects with high energy requirements:
e.g. mobile phones, power tools * require special handling, containment & disposal
* limited interchangeability * long life time * produce smaller amount of waste (flat discharge curve) * high energy efficiency * used in situations where charging is practical
* lower energy density: part of battery space used in design to accommodate re-charging * lower initial voltage * may not always be readily operational, must be charged * low internal resistance * Materials used: * nickel-metal-hydride (NiMH) * high specific energy * fewer toxic metals than (NiCd) * used in medical instruments * lithium-manganese (LiMN2O4) * high charge & discharge current * low specific energy * short-medium length service life * used in power tools
Batteries are divided into two categories:
PRIMARY BATTERIES * non-rechargeable * low cost (short-term) high cost (long-term) * used in objects with low energy requirements:
e.g. hearing aids, watches, remote controls * do not require special handling, containment & disposal * higher level of interchangeability * short life time * produce larger amount of waste (sloping discharge curve) * low energy efficiency * used in situations where recharging is impractical:
e.g. forest-fire services * higher energy density
* higher initial voltage * readily operational
* high internal resistance * Materials used: * lithium iron disulfide (Li-FeS2) * high capacity * low internal resistance * low performance