Peapod-like Li3VO4/N-Doped Carbon Nanowires with Pseudocapacitive Properties as Advanced Materials for High-Energy Lithium-Ion Capacitors

4 years ago

Peapod-like Li3VO4/N-Doped Carbon Nanowires with Pseudocapacitive Properties as Advanced Materials for High-Energy Lithium-Ion Capacitors

Yan Yu, Shuangqiang Chen, Laifa Shen, Xiaojun Wu, Peter A. van Aken, Haifeng Lv, Joachim Maier, Peter Kopold

Lithium ion capacitors are new energy storage devices combining the complementary features of both electric double-layer capacitors and lithium ion batteries. A key limitation to this technology is the kinetic imbalance between the Faradaic insertion electrode and capacitive electrode. Here, we demonstrate that the Li3VO4 with low Li-ion insertion voltage and fast kinetics can be favorably used for lithium ion capacitors. N-doped carbon-encapsulated Li3VO4 nanowires are synthesized through a morphology-inheritance route, displaying a low insertion voltage between 0.2 and 1.0 V, a high reversible capacity of ≈400 mAh g−1 at 0.1 A g−1, excellent rate capability, and long-term cycling stability. Benefiting from the small nanoparticles, low energy diffusion barrier and highly localized charge-transfer, the Li3VO4/N-doped carbon nanowires exhibit a high-rate pseudocapacitive behavior. A lithium ion capacitor device based on these Li3VO4/N-doped carbon nanowires delivers a high energy density of 136.4 Wh kg−1 at a power density of 532 W kg−1, revealing the potential for application in high-performance and long life energy storage devices. Peapod-like Li3VO4⊂N-doped carbon nanowires with low Li-ion insertion potential and fast rate kinetics can be favorably used for lithium-ion capacitors that achieve both high energy density and high power density. It is found that small nanoparticles, low energy-diffusion barrier and highly localized charge transfer together give rise to a high-rate pseudocapacitive behavior of Li3VO4.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adma.201700142