摘要
Recently, owing to the increasing demand for wearable electronics, it is necessary to investigate flexible and highly safe energy storage devices. Commonly used energy storage devices, such as lithium-ion batteries and supercapacitors with organic electrolytes, may suffer from fire and explosion. Therefore, zinc-ion capacitors (ZICs) with nontoxic and nonflammable aqueous electrolytes have recently attracted considerable attention. In this study, high-surface-area nanoporous core-shell-structured multiwalled carbon nanotube@graphene oxide nanoribbon (NP-MWCNT@GONR) is used as the cathode material in aqueous ZICs for the first time. These ZICs exhibit a high energy density of 90 Wh kg −1 at 95 W kg −1 and a high power density of 19 kW kg −1 at 31 Wh kg −1 . The cycling retention is 86.5% after 200 cycles; however, the device fails after 200 cycles owing to the formation of zinc dendrites on the anode. To suppress dendrite formation, NP-MWCNT@GONR-coated zinc anode and freeze-dried gel electrolyte are used, and the cycle life is extended beyond 2000 cycles. In-situ synchrotron transmission X-ray microscopy is performed during charging and discharging, which demonstrates that the gel electrolyte and the NP-MWCNT@GONR-coated zinc anode can effectively inhibit dendrite formation. This study reveals that ZICs with NP-MWCNT@GONR cathodes, NP-MWCNT@GONR-coated zinc anode, and gel electrolytes are highly safe energy storage devices for use in flexible and wearable electronics.