Topotactically synthesized ultralong LiV3O8 nanowire cathode materials for high-rate and long-life rechargeable lithium batteries

High-power applications at fast charge and discharge rates are still significant challenges in the development of rechargeable lithium (Li) batteries. Here, we demonstrate that ultralong LiV3O8 nanowire cathode materials synthesized by topotactic Li intercalation are capable of excellent high-rate performance with minimal capacity loss. A specific discharge capacity of 176 mAh g−1 can be obtained at the current density of 1500 mA g−1, and the capacity is able to stabilize at 160 mAh g−1 after 400 cycles, corresponding to 0.025% capacity fading per cycle. For current density up to 2000, mA g−1, the initial and the six-hundredth cycle capacities can reach 137 and 120 mAh g−1, respectively, corresponding to a capacity fading of only 0.022% per cycle. The ability to provide this level of performance is attributed to a low-charge-transfer resistance, good structural stability, large surface area and suitable degree of crystallinity, and it indicates that LiV3O8 nanowires are promising cathode materials for use in high-rate and long-life rechargeable Li batteries. Li-Qiang Mai and co-workers at Wuhan University of Technology and Harvard University have revealed that efficient rechargeable lithium batteries can be built using ultra-long nanowires as electrodes. With the advent of mobile devices, there has been a growing need for electrical charges to be stored in ever smaller spaces, yet at the same time taken up and released increasingly rapidly — but this trade-off between high-energy densities and high-power densities is not easy to achieve. Although rechargeable lithium batteries already present good stability and storage capacity, they need to be charged and discharged much more rapidly. Lithium vanadium oxide (LiV3O8) — which features lithium ions intercalated between vanadium oxide layers — is an efficient cathode material whose rate performance can be altered by tuning its morphology. Mai and colleagues have now shown a facile route to prepare ultra-long, crystalline LiV3O8 nanowires that endow batteries with excellent stability over time as well as high-rate performances. High-power applications at fast charge and discharge rates are still great challenges in the development of rechargeable lithium batteries. Here, we demonstrate that ultralong LiV3O8 nanowire cathode materials synthesized by topotactic Li intercalation present excellent high-rate and long-life performance. At the current density of 2000, mA g−1, the initial and the six-hundredth discharge capacities can reach 137 and 120 mAh g−1, respectively, corresponding to a capacity fading of only 0.022% per cycle. Such performance indicates that the topotactically synthesized ultralong LiV3O8 nanowires are promising cathode materials for high-rate and long-life rechargeable lithium batteries.