The effect of succinic anhydride (SA) as an electrolyte additive on the cycling performance of Li electrode is discussed. As the SA content in the electrolyte increased from 2 to 5 to 10 wt%, the capacity retention of LiCoO2/Li cell is greatly improved owing to the modification of the solid electrolyte interphase (SEI) layer and the suppression of dendrite growth on the Li electrode. In particular, when 10 wt% SA is introduced into the electrolyte, the Li electrode thickness increases only about 45 μm (from 100 to 145 μm) after 40 cycles, whereas an increase of about 210 μm occurs without SA. This amazing enhancement in cycling performance is also augmented by a much smaller increase in the bulk resistance of the LiCoO2/Li cell after cycling with 10 wt% SA.