ABSTRACT
Put it simply, batteries are devices that can convert chemical energy into electricity by the oxidation or reduction of active species. This process is reversible such that the system can be used for both energy storage and electricity delivery. Normally, batteries from different active species could meet specic EES applications such as UPS (uninterrupted power supply), grid support and energy management, according to their range requirement of power rate and capacity (Figure 9.1). For large-scale energy storage systems (grid support), it could be realised via lead-acid batteries, sodium-sulphur, lithium ions and ow batteries. Although lead-acid battery is a mature technology, its short lifetime and low deep discharge ability limited its usage in large-scale energy storage.
