Developing electrode materials with high-energy densities is important for the development of lithium-ion batteries. Here, we demonstrate a mesoporous molybdenum dioxide material with abnormal lithium-storage sites, which exhibits a discharge capacity of 1,814 mAh g^-1 for the first cycle, more than twice its theoretical value, and maintains its initial capacity after 50 cycles. Contrary to previous reports, we find that a mechanism for the high and reversible lithium-storage capacity of the mesoporous molybdenum dioxide electrode is not based on a conversion reaction. Insight into the electrochemical results, obtained by in situ X-ray absorption, scanning transmission electron microscopy analysis combined with electron energy loss spectroscopy and computational modelling indicates that the nanoscale pore engineering of this transition metal oxide enables an unexpected electrochemical mass storage reaction mechanism, and may provide a strategy for the design of cation storage materials for battery systems.

Nature Communications 7, Article number: 11049 doi:10.1038/ncomms11049

http://www.nature.com/ncomms/2016/160322/ncomms11049/full/ncomms11049.html

开发具有高能量密度的电极材料对提升锂离子电池的性能十分重要。Shon等人报道了一种包含非正常锂储能位点的多孔二氧化钼材料，其首次的放电容量达到1,814 mAh g^-1，是理论值的两倍多。与早前报道的不同，他们发现这种二氧化钼电极的高能量密度并非来自于转化反应。通过对电化学过程的深入研究发现，这种过渡金属的纳米孔洞有意想不到的高储能反应发生。作者称这一发现或许为设计新型电池系统提供了思路。（Nature Communications DOI:10.1038/ncomms11049）（新材料在线）