Tripropyl borate was investigated as a low cost anion receptor to improve the performance of lithium-ion cells. The impact of tripropyl borate was examined using lithium-ion cells comprising a negative electrode of mesocarbon microbeads, a positive electrode of Li 1.1 [Mn 1/3 Ni 1/3 Co 1/3 ] 0.9 O 2 and an LiPF 6 -based electrolyte. It was found that the performance of the cells was improved by adding a proper amount of tripropyl borate (≤0.1wt%) to the LiPF 6 -based electrolyte. However, a small amount of gas was observed from cells with high contents of tripropyl borate when cycled at 55°C, and as a result, the performance of the cells deteriorated.