Iranian Nanotechnology Society International Journal of Nanoscience and Nanotechnology 1735-7004 17 4 2021 11 01 Rational Design of Phosphorus Abundant Co2P Nanoparticles Encapsulated by Nitrogen-doped Carbon Nanotubes for Superior Lithium Ion Capacitors with 4.5 Voltage 239 248 247642 EN J. Xu North China University of Water Resources and Electric Power, Zhengzhou 450000, PR China H. Guo North China University of Water Resources and Electric Power, Zhengzhou 450000, PR China Journal Article 2021 06 11 <em>   The sluggish reaction kinetics and aggregation of volume during lithiation/delithiation process are the main obstacles of anode for li-ion capacitors (LICs). Here, we use the “three bird one stone” strategy to design the anode of phosphorus abundant Co₂P nanoparticles encapsulated by N-doped CNTs rationally. The Co₂P nanoparticles contribute to shorten the Li⁺ diffusion length, while abundant phosphorus guaranteeing the high electrical conductivity and N-CNTs providing stable structure protecting layers. Hence, Co₂P/N-CNTs electrode reveals a large specific capacity of 807 mAh g^-1 at 0.1 A g^-1 over 200 cycles and excellent rate performance of 395 mAh g^-1 at 3.2 A g^-1. Extraordinary, the capacitive contribution of Co₂P/N-CNTs electrode at 1 mV s^-1 is 80.73%, contributing to the enhanced reaction kinetics and rate capacity. The LICs comprising of Co₂P/N-CNTs anode and activated carbon (AC) cathode demonstrate an outstanding energy density of 130 Wh kg^-1 at 625 W kg^-1 along with 90.24% capacity retention over 10000 cycles at 5 A g^-1 within 4.5 V. The proposed strategy can be applied to develop promising electrode materials for promising energy storage systems.</em> https://www.ijnnonline.net/article_247642_eb620d8074973b3700ba0098c7ebf71c.pdf