How long will lithium-ion batteries last for in years?

The forecast working life of a lithium battery set for an uninterruptible power supply is 10 years. Lithium batteries lose their ability to store electric charge over time due to a parasitic solid that forms on the negative electrodes of the battery that prevents lithium-ions from moving through the plating. In comparison the standard lead acid battery has a design life of 5 years with replacement in years 3-4 or 10 years with replacement in years 7-8.