An artificial while very stable solid electrolyte interphase film is formed on lithium metal using an electrochemical strategy. When this protected Li anode is first used in a Li–O2 battery, the film ...formed on the anode can effectively suppress the parasitic reactions on the Li anode/electrolyte interface and significantly enhance the cycling stability of the Li–O2 battery.
Inspired by the favorable structure and shape of golden‐toad eggs, a self‐standing macroporous active carbon fiber electrode is designed and fabricated via a facile and scalable strategy. After being ...decorated with ruthenium oxide, it endows Li–O2 batteries with superior electrochemical performances.
To recycle rusty stainless‐steel meshes (RSSM) and meet the urgent requirement of developing high‐performance cathodes for potassium‐ion batteries (KIB), we demonstrate a new strategy to fabricate ...flexible binder‐free KIB electrodes via transformation of the corrosion layer of RSSM into compact stack‐layers of Prussian blue (PB) nanocubes (PB@SSM). When further coated with reduced graphite oxide (RGO) to enhance electric conductivity and structural stability, the low‐cost, stable, and binder‐free RGO@PB@SSM cathode exhibits excellent electrochemical performances for KIB, including high capacity (96.8 mAh g−1), high discharge voltage (3.3 V), high rate capability (1000 mA g−1; 42 % capacity retention), and outstanding cycle stability (305 cycles; 75.1 % capacity retention).
Turning waste into treasure: Rusty stainless steel meshes were utilized as solid‐state iron sources with excellent conductivity properties in order to fabricate stable, low‐cost, and flexible binder‐free potassium‐ion battery electrodes. When combined with unique structural design, the reduced graphite oxide‐coated electrodes exhibited high capacities, superior rate capabilities, and excellent cycle performance.
To turn waste into treasure, a facile and cost‐effective strategy is developed to revive electroless nickel plating wastewater and cotton‐textile waste toward a novel electrode substrate. Based on ...the substrate, a binder‐free PB@GO@NTC electrode is obtained, which exhibits superior electrochemical performance. Moreover, for the first time, a novel tube‐type flexible and wearable sodium‐ion battery is successfully fabricated.
Rechargeable sodium–oxygen (Na–O2) batteries are of interest due to their high specific capacity, high equilibrium potential output, and the abundance of sodium resources; however, their cycle life ...is still very poor due to instability of electrolytes and especially the uncontrollable growth of Na dendrites. Herein, as a proof‐of‐concept experiment, a facile and low‐cost strategy is first proposed and demonstrated to effectively suppress growth of Na dendrites by using a fibrillar polyvinylidene fluoride film (f‐PVDF) with nonthrough pore as a multifunctional blocking interlayer. Unexpectedly, the f‐PVDF interlayer endows Na–O2 battery with superior electrochemical performances, including high rate capability and long cycle life (up to 87 cycles), which is superior to those of the compact PVDF (c‐PVDF), PVDF with through pores (p‐PVDF), polyethylene oxide (PEO), and conventional polytetrafluoroethylene (PTFE) counterparts due to the following combined advantages: (1) the stronger CF polar function groups provide a better affinity to Na ions, thus enabling a more homogeneous Na deposition than that of CO function groups in PEO interlayer; (2) compared with c‐PVDF and p‐PVDF interlayers, f‐PVDF holds more electrolyte uptake for higher ion conductivity; (3) the good wettability of the f‐PVDF interlayer with electrolyte benefits Na dendrite suppression compared with PTFE interlayer.
Stable and fibrillar polyvinylidene fluoride films (f‐PVDFs) with strongly polar functional groups are prepared as the blocking interlayer for Na dendrites suppression. Surprisingly, the films efficiently suppress dendrite formation and greatly improve the cycle life of Na–O2 batteries, which is attributed to f‐PVDF's high electrolyte uptake, good adhesion to Na ionic flux, and excellent affinity to the electrolyte.
To promote the development of high energy Li–O2 batteries, it is important to design and construct a suitable and effective oxygen‐breathing cathode. Herein, activated cobalt‐nitrogen‐doped carbon ...nanotube/carbon nanofiber composites (Co‐N‐CNT/CNF) as the effective cathodes for Li–O2 batteries are prepared by in situ chemical vapor deposition (CVD). The unique architecture of these electrodes facilitates the rapid oxygen diffusion and electrolyte penetration. Meanwhile, the nitrogen‐doped carbon nanotube/carbon nanofiber (N‐CNT/CNF) and Co/CoNx serve as reaction sites to promote the formation/decomposition of discharge product. Li–O2 batteries with Co‐N‐CNT/CNF cathodes exhibit superior electrochemical performance in terms of a positive discharge plateau (2.81 V) and a low charge overpotential (0.61 V). Besides, Li–O2 batteries also present a high discharge capacity (11512.4 mAh g−1 at 100 mA g−1), and a long cycle life (130 cycles). Meanwhile, the Co‐N‐CNT/CNF cathode also has an excellent flexibility, thus the assembled flexible battery with Co‐N‐CNT/CNF can work normally and hold a wonderful capacity rate under various bending conditions.
Activated cobalt‐nitrogen‐doped carbon nanotube/carbon nanofiber composites (Co‐N‐CNT/CNF) cathodes are prepared via in situ chemical vapor deposition. The Li–O2 batteries with these cathodes exhibit great performances. Meanwhile, Co‐N‐CNT/CNF cathodes are flexible, based on which the assembled flexible battery exhibits great performances and flexibility under various bending conditions.
A flexible freestanding air cathode inspired by traditional Chinese calligraphy art is built. When this novel electrode is employed as both a new concept cathode and current collector, to replace ...conventional rigid and bulky counterparts, a highly flexible and foldable Li–O2 battery with excellent mechanical strength and superior electrochemical performance is obtained.
To meet the increasing demands for portable and flexible devices in a rapidly developing society, it is urgently required to develop highly safe and flexible electrochemical energy‐storage systems. ...Flexible lithium–oxygen batteries with high theoretical specific energy density are promising candidates; however, the conventional half‐open structure design prevents it from working properly under water or fire conditions. Herein, as a proof‐of‐concept experiment, a highly safe flexible lithium–oxygen battery achieved by the synergy of a vital multifunctional structure design and a unique composite separator is proposed and fabricated. The structure can effectively prevent the invasion of water from the environment and combustion, which is further significantly consolidated with the help of a polyimide and poly(vinylidene fluoride‐co‐hexafluoropropylene) composite separator, which holds good water resistance, thermal stability, and ionic conductivity. Unexpectedly, the obtained lithium–oxygen battery exhibits superior flexibility, water resistance, thermal resistance, and cycling stability (up to 218 cycles; at a high current of 1 mA and capacity of 4 mA h). This novel water/fireproof, flexible lithium–oxygen battery is a promising candidate to power underwater flexible electronics.
A highly safe flexible lithium–oxygen (SFLO) battery is designed and fabricated to endow the possibility to power versatile portable and flexible devices. Thanks to an innovative assembly method, the structure of the SFLO battery possesses good flexibility, excellent water‐ and fire‐resistance, and superior electrochemical performances.
An ultrathin, lightweight, and wearable Li‐O2 battery with a novel segmented structure is first fabricated by employing a “break up the whole into parts” strategy. Superior battery performance ...including low overpotential, high specific capacity, good rate capability, excellent cycle stability, and high gravimetric/volumetric energy density (294.68 Wh kg−1/274.06 Wh L−1) is successfully achieved even under repeatedly various deformation.
The successful development of Li–O2 battery technology depends on resolving the issue of cathode corrosion by the discharge product (Li2O2) and/or by the intermediates (LiO2) generated during cell ...cycling. As an important step toward this goal, we report for the first time the nanoporous Ni with a nanoengineered AuNi alloy surface directly attached to Ni foam as a new all-metal cathode system. Compared with other noncarbonaceous cathodes, the Li–O2 cell with an all-metal cathode is capable of operation with ultrahigh specific capacity (22,551 mAh g–1 at a current density of 1.0 A g–1) and long-term life (286 cycles). Furthermore, compared with the popularly used carbon cathode, the new all-metal cathode is advantageous because it does not show measurable reactivity toward Li2O2 and/or LiO2. As a result, extensive cyclability (40 cycles) with 87.7% Li2O2 formation and decomposition was obtained. These superior properties are explained by the enhanced solvation-mediated formation of the discharge products as well as the tailored properties of the all-metal cathode, including intrinsic chemical stability, high specific surface area, highly porous structure, high conductivity, and superior mechanical stability.
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