Strongly coupled metal oxide nanorod arrays with graphene nanoribbons and nanosheets enable novel solid-state hybrid cells

• MOx nanorod arrays are grown on the carbon fiber papers via a hydrothermal method.
• GNR and GNS are deposited on the MOx nanorods via a facile dipping-coating method.
• The electrochemical performance is enhanced with the introduction of GNR and GNS.
• A high performance (MOx/GNR)@GNS-based solid-stated cells is successfully achieved.

Electrochemical capacitors and rechargeable batteries are still limited in applications by the low energy and power densities they can deliver, respectively, holding back their deployment in electric vehicles. Here we develop a type of solid-state hybrid cells (SHCs) composed of graphene nanoribbons and nanosheets-coated metal oxide nanorod arrays ((MOx/GNR)@GNS). GNR and GNS are deposited on the surface of MOx nanorod arrays to improve the electron transport characteristic, and thus enhance the energy storage performance. The (MOx/GNR)@GNS-based SHCs can achieve a maximum volumetric energy density of 0.9 mWh cm−3, and still retain 0.4 mWh cm−3 even at 0.1 W cm−3. The energy storage performance is much better than the electrochemical capacitors reported previously, and can even rival the commercial Li thin-film battery but with a significantly higher power density, lower cost and higher safety. Also demonstrated is the good long-term cycle life with only ∼17% loss after 2500 cycles. These salient features make the (MOx/GNR)@GNS composites-based SHCs a strong contender for electrochemical energy storage.

Figure optionsDownload as PowerPoint slide