Jump to main content
Jump to site search


Ultrafine Co2P nanorods wrapped by graphene enable a long cycle life performance for a hybrid potassium-ion capacitor

Author affiliations

Abstract

Given their high theoretical capacities, metal phosphides are anticipated to be excellent charge-storage materials for high-efficiency potassium-ion batteries. However, one of the major problems is the shuttling of heavy and large K+ ions between electrodes, which triggers rapid capacity fading. Here, we demonstrate that sub-4 nm Co2P nanorods attached to reduced graphene oxide (Co2P@rGO) can operate at a lifespan exceeding thousands of cycles. By taking advantage of the high electronic conductivity and flexibility of reduced graphene oxide (rGO), the composite electrode delivers a high capacity (374 mA h g−1 at 20 mA g−1) and excellent C-rate capability (141 mA h g−1 at 2 A g−1), superior to its commercial counterpart. Impressively, the electrode maintains 54% of the capacity over 5000 cycles, and there is almost no capacity fading after the initial 200 cycles. In addition, a hybrid potassium-ion capacitor, assembled from a Co2P@rGO anode and activated carbon cathode, affords a high energy/power density (87 W h kg−1 and 4260 W kg−1) in a potential window of 1.0–4.0 V, as well as a long lifespan of over 1000 cycles. These extremes demonstrate the high-performance of the Co2P@rGO anode materials and an optimal synthesis strategy to boost K+ storage performance.

Graphical abstract: Ultrafine Co2P nanorods wrapped by graphene enable a long cycle life performance for a hybrid potassium-ion capacitor

Back to tab navigation

Supplementary files

Publication details

The article was received on 01 Apr 2019, accepted on 11 Jun 2019 and first published on 11 Jun 2019


Article type: Communication
DOI: 10.1039/C9NH00211A
Nanoscale Horiz., 2019, Advance Article

  •   Request permissions

    Ultrafine Co2P nanorods wrapped by graphene enable a long cycle life performance for a hybrid potassium-ion capacitor

    Y. Wang, Z. Zhang, G. Wang, X. Yang, Y. Sui, F. Du and B. Zou, Nanoscale Horiz., 2019, Advance Article , DOI: 10.1039/C9NH00211A

Search articles by author

Spotlight

Advertisements