Combination of Li-rich layered-oxide with O2 cathodes for high-energy Li-ion/Li-O2 hybrid batteries

The energy density of commercial Li-ion batteries (LIBs) is limited by the specific capacity of intercalation-type cathodes. The Li-O-2 batteries based on the conversion reaction of oxygen cathodes can deliver the superhigh specific capacity. Herein, the Li-rich layered-oxide 0.5Li(2)MnO(3)center dot 0.5LiNi(0.54)Co(0.16)Mn(0.16)O(2) (5/5 LLO) cathodes have been combined with O-2 cathodes, in order to examine their synergistic effect on cell performance. It is found that the hybrid cells deliver the discharge capacity of 458 mAh g(cathode)(-1) at approximately 0.2 C, compared with the specific capacity 200 mAh g(cathode)(-1) at 0.2 C of 5/5 LLO in LIB. Meanwhile, the cycle life of Li-O-2 batteries under 100% depth of discharge increases from a few cycles to more than 20 cycles, attributed to the transition of Ni2+ to Ni4+ upon charging that promotes decomposition of reaction products Li2O2 and by-products Li2CO3. These results demonstrate that the hybrid Li-ion/Li-O-2 battery is a powerful way for combining advantages of the intercalation and conversion-type cathodes, promising for construction of future high-energy batteries. Published under an exclusive license by AIP Publishing.

Automated summary

Li-O-2 batteries based on the conversion reaction of oxygen cathodes can deliver high specific capacity. Combining Li-rich layered-oxide cathodes with oxygen cathodes improves cell performance and extends cycle life.