KTi2(PO4)3 with Large Ion Diffusion Channel for High-Efficiency Sodium Storage

5 years ago

KTi2(PO4)3 with Large Ion Diffusion Channel for High-Efficiency Sodium Storage

Yanan Xu, Jinzhi Sheng, Qinyou An, Xu Xu, Haoying Lyu, Chen Peng, Liqiang Mai

To accommodate the decreasing lithium resource and ensure continuous development of energy storage industry, sodium-based batteries are widely studied to inherit the next generation of energy storage devices. In this work, a novel Na super ionic conductor type KTi2(PO4)3/carbon nanocomposite is designed and fabricated as sodium storage electrode materials, which exhibits considerable reversible capacity (104 mAh g−1 under the rate of 1 C with flat voltage plateaus at ≈2.1 V), high-rate cycling stability (74.2% capacity retention after 5000 cycles at 20 C), and ultrahigh rate capability (76 mAh g−1 at 100 C) in sodium ion batteries. Besides, the maximum ability for sodium storage is deeply excavated by further investigations about different voltage windows in half and full sodium ion cells. Meanwhile, as cathode material in sodium-magnesium hybrid batteries, the KTi2(PO4)3/carbon nanocomposite also displays good electrochemical performances (63 mAh g−1 at the 230th cycle under the voltage window of 1.0–1.9 V). The results demonstrate that the KTi2(PO4)3/carbon nanocomposite is a promising electrode material for sodium ion storage, and lay theoretical foundations for the development of new type of batteries. Novel NASICON-type KTi2(PO4)3 provides a flat discharge voltage plateau, which is a promising electrode for sodium storage. A KTi2(PO4)3/carbon nanocomposite is constructed via a co-precipitation method followed by an annealing process, exhibiting superior ultrahigh rate capability (76 mA h g−1 at 100 C) and excellent high-rate cycling stability (74.2% capacity retention after 5000 cycles at 20 C).

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

DOI: 10.1002/aenm.201700247