Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1284729 | Journal of Power Sources | 2011 | 6 Pages |
A lithium-ion positive electrode is proposed that contains both high energy density and efficient pulse power capability, even at low state-of-charge (SOC). The pulse power capability at low SOC is attractive for applications, such as plug-in hybrid electric vehicles (PHEVs), which require pulse power operation over the entire useable SOC window. A lithium- and manganese-rich transition-metal layered-oxide (LMR-NMC), also classified as a layered–layered oxide material, is blended with a lithium iron phosphate (LFP) to achieve a potentially low-cost, high-performance electrode. The LMR-NMC material provides high energy by delivering cathode material gravimetric energy densities greater than 890 Wh kg−1. The pulse power capability of this material at low SOC is greatly improved by incorporating a modest quantity of LFP. The LFP serves as an internal redox couple to charge and discharge the more rate-limited LMR-NMC material at moderate to low SOCs.
► Lithium iron phosphate is blended with a high-capacity layered oxide cathode. ► The impedance of the composite electrode is lowered at low states of charge. ► Rate capability is improved without penalizing lifetime or energy density.