Energy valve-regulated lead-acid batteries

Spanos C, Turney DE, Fthenakis V (2015) Life-cycle analysis of flow-assisted nickel zinc-, manganese dioxide-, and valve-regulated lead-acid batteries designed for demand-charge reduction. Renew Sustain Energy Rev 43 478-494. doi 10.1016/j.rser.2014.10.072... 

Different types of lead-acid batteries have been developed as energy sources for many power applications, like traction and backup or standby power systems. The flooded lead-acid batteries have an excess or flooded electrolyte and they were the largest used at the beginning of the last century for many applications. Valve-regulated lead-acid (VRLA) batteries were developed as an alternative to the flooded lead-acid batteries, in order to maintain levels of distilled water and prevent drying of cells, which means safe operation for battery packs in electric... 

Valve-regulated lead-acid (VRLA) batteries can be small in size, which results in a high ratio between the inactive and active materials used. Consequently, the specific energy is low when immobilized electrolytes are used, the utilization of the active materials is decreased. In this case, however, the lower H2SO4 reservoir, and partially the upper one, too, are removed, resulting in a higher volume specific energy. 

Lead-acid batteries will continue to have, by far, the major share of the standby battery market, due to their outstanding specific-energy, life and cost characteristics. It is expected that there will be a significant growth of the standby battery market during the next few years. Most standby batteries already have the valve-regulated... 

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