The booming market of portable and wearable electronics has aroused the requests for advanced flexible selfpowered energy systems featuring both excellent performance and high safety. Herein, we report a safe, flexible, self-powered wristband system by integrating high-performance zinc-ion batteries (ZIBs) with perovskite solar cells (PSCs). ZIBs were first fabricated on the basis of a defective MnO 2−x nanosheetgrown carbon cloth (MnO 2−x @CC), which was obtained via the simple lithium treatment of the MnO 2 nanosheets to slightly expand the interlayer spacing and generate rich oxygen vacancies. When used as a ZIB cathode, the MnO 2−x @CC with a ultrahigh mass loading (up to 25.5 mg cm −2 ) exhibits a much enhanced specific capacity (3.63 mAh cm −2 at current density of 3.93 mA cm −2 ), rate performance, and long cycle stability (no obvious degradation after 5000 cycles) than those of the MnO 2 @CC. Importantly, the MnO 2−x @CC-based quasi-solid-state ZIB not only achieves excellent flexibility and an ultrahigh energy density of 5.11 mWh cm −2 (59.42 mWh cm −3 ) but also presents a high safety under a wide temperature range and various severe conditions. More importantly, the flexible ZIBs can be integrated with flexible PSCs to construct a safe, selfpowered wristband, which is able to harvest light energy and power a commercial smart bracelet. This work sheds light on the development of high-performance ZIB cathodes and thus offers a good strategy to construct wearable self-powered energy systems for wearable electronics.
Perovskite solar cells (PSCs) have achieved remarkable progress with high power conversion efficiency (PCE) and low cost. However, there is still huge room for improvement in terms of long-term stability,...
SnO 2 has been the most commonly used electron transport layer (ETL) in perovskite solar cells (PSCs) due to its excellent electron mobility and stability. To meet the applications of SnO 2 ETL in large-scale solar cells, a rapid but inexpensive synthesis of high-quality SnO 2 film is urgently needed. Herein, SnO 2 quantum dots (QDs) were synthesized through a super rapid (∼3 min), additive-free microwave-assisted reaction. Comparing with the crystalized SnO 2 films, the small-sized SnO 2 QDs present improved electronic properties, including the Fermi level, conductivity, electron mobility, and trap density. Hence, with this SnO 2 ETL, the power conversion efficiency of the PSCs reached 20.24% using a CH 3 NH 3 PbI 3 absorber, which is among the highest values in the same rank. Overall, these results demonstrate a bright future for the facile microwave-assisted synthesis of SnO 2 QDs along with their application for highly flexible and efficient PSCs.
The development of
solid-state electrolytes (SSEs) for high energy
density lithium metal batteries (LMBs) usually needs to take into
account of the interfacial compatibility against lithium metal and
the electrolyte stability suitable for a high-potential cathode. In
this study, through a facile two-step coating process, novel double-layer
solid composite electrolytes (SCEs) with Janus characteristics are
customized for the high-voltage LMBs with improved room-temperature
cycling performance. Among which, high-voltage resistant poly(vinylidene
fluoride) (PVDF) is adopted here for the construction of an electrolyte
layer facing the cathode, while the other layer against the lithium
anode is composed of the polymer matrix of poly(ethylene oxide) (PEO)
blended with PVDF to obtain a lithium metal-friendly interface. With
the further incorporation of Laponite clay, the PVDF/(PEO+PVDF)-L
SCEs not only exhibit improved mechanical properties, but also achieve
a highly increased ionic conductivity (5.2 × 10–4 S cm–1) and lithium ion migration number (0.471)
at room temperature. The assembled NCM523|PVDF/(PEO+PVDF)-L
SCEs|Li cells thus are able to deliver the initial discharge capacity
of 153.9 mAh g–1 with 80.8% capacity retention after
200 cycles at 0.3 C. Such easily manufactured double-layer SCEs capable
of operating steadily at room temperature provide a competitive electrolyte
option for high-voltage solid-state LMBs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.