Chinese researchers say that high-rate, long-life batteries could be one step closer, thanks to nanofiber anodes.

Lithium-ion batteries (LIBs) have become the go-to option for smartphones and other devices thanks to their high energy density and long life. Despite their mass-adoption, further advances in their development continue to hit research headlines. The latest contribution to this growing field comes from a paper published in Materials Today Energy [DOI: 10.1016/ j.mtener.2016.11.002]. In it, authors have shown that anodes made from ultra-long, electrospun BaLi2Ti6O14 nanofibers could improve the performance of these batteries.

Most commercial LIBs use graphite anodes, but the formation of an amorphous solid electrolyte interphase (SEI) layer over each charge-discharge cycle reduces their lifetime. Anodes made from lithium titanium oxide (Li4Ti5O12) offer better cycling performance because they don’t form an amorphous layer, but their low packing density limits their ability to store charge. In order to produce an electrode that displays both high density and optimal cycling, Prof Jie Shu and his team from Ningbo University looked to the nanoscale.

Their BaLi2Ti6O14 nanofibers were synthesised by electrospinning and subsequent annealing. The fibres were then mixed with carbon black to form a slurry, which coated copper foil to form a working anode. In electrochemical tests, the anode showed high electrical stability – the charge-discharge curves remained consistent across all current densities (200, 500 and 1000 mA g-1). In addition, charge capacities reduced only slightly as current densities increased. For example, when the anode was cycled at 1000 mA g-1, its capacity decayed by 0.153% per cycle, reducing from 140.2 to 123 mA g-1 over 800 cycles.

The authors attribute this behaviour to the high rate of electron transport facilitated by the 1-D structure of the fibres – this nanostructured Li4Ti5O12 was shown to display lower ohmic resistance than the bulk material. TEM analysis showed that the nanofiber anode is remarkably structurally stable, changing only minimally over 800 charge-discharge cycles, and displaying excellent reversibility. Though still at a relatively early stage of development, the authors believe that their electrochemical properties “render the nanofibers as promising anode materials for commercial LIBs.”


X. Wu, X. Li, C. Zhu, P. Li, H. Yu, Z. Guo, J. Shu, “Electrospun one-dimensional BaLi2Ti6O14 nanofibers for high rate performing lithium-ion battery” Materials Today Energy 1-2 (2016) 17-23 DOI: 10.1016/j.mtener.2016.11.002