Abstract In the past decade, there have been exciting developments in field of lithium ion batteries as energy storage devices, resulting application areas ranging from small portable electric devices to large power systems such hybrid vehicles. However, maximum density current having topatactic chemistry is not sufficient meet demands new markets Therefore, electrochemical with higher densities are being sought, and metal‐air conversion considered a promising candidate. More recently,...

Abstract Electrical energy storage and conversion is vital to a clean, sustainable, secure future. Among all electrochemical devices, metal‐air batteries have potential offer the highest density, representing most promising systems for portable (electronics), mobile (electrical vehicles), stationary (micro‐grids) applications. To date, however, many fundamental issues are yet be overcome realize this potential. For example, efficient catalysts oxygen reduction reaction (ORR) evolution (OER)...

A cable-type flexible Zn-air battery with a spiral zinc anode, gel polymer electrolyte (GPE), and air cathode coated on nonprecious metal catalyst is designed in order to extend its application area toward wearable electronic devices.

The development of catalysts with earth-abundant elements for efficient oxygen evolution reactions is paramount significance clean and sustainable energy storage conversion devices. Our group demonstrated recently that the electrochemical tuning via lithium insertion extraction has emerged as a powerful approach to improve catalytic activity. Here we report novel in situ oxidation develop series binary, ternary, quaternary transition metal (e.g., Co, Ni, Fe) oxides from their corresponding...

Abstract La 0.3 (Ba 0.5 Sr ) 0.7 Co 0.8 Fe 0.2 O 3− δ is a promising bifunctional perovskite catalyst for the oxygen reduction reaction and evolution reaction. This has circa 10 nm‐scale rhombohedral LaCoO 3 cobaltite particles distributed on surface. The dynamic microstructure phenomena are attributed to charge imbalance from replacement of A‐site cations with 3+ local stress Co‐site sub‐lattice cubic structure.

Portable power sources and grid-scale storage both require batteries combining high energy density low cost. Zinc metal battery systems are attractive due to the cost of zinc its charge-storage capacity. However, under repeated plating stripping, anodes undergo a well-known problem, dendrite formation, causing internal shorting. Here we show backside-plating configuration that enables long-term cycling without We demonstrate 800 stable cycles nickel-zinc with good rate (20 mA cm(-2), 20 C...

Inspired by the tetrapod structures of a breakwater, highly efficient electrocatalyst for oxygen reduction reaction (ORR) in alkaline solution has been created from low-cost, commercial melamine foam and ketjenblack. The unique porous architecture greatly facilitates rapid mass transport, while N-doped ketjenblack Fe/Fe3C-functionalized surface framework dramatically enhance ORR activity. Detailed facts importance to specialist readers are published as "Supporting Information". Such...

A composite air electrode consisting of Ketjenblack carbon (KB) supported amorphous manganese oxide (MnOx) nanowires, synthesized via a polyol method, is highly efficient for the oxygen reduction reaction (ORR) in Zn-air battery. The low-cost and conductive KB this overcomes limitations due to low electrical conductivity MnOx while acting as supporting matrix catalyst. large surface area together with other microscopic features (e.g., high density defects), potentially offers more active...

While pseudocapacitors represent a promising option for electrical energy storage, the performance of existing ones must be dramatically enhanced to meet today's ever-increasing demands many emerging applications. Here we report nanostructured, mixed-valent manganese oxide film that exhibits anomalously high specific capacitance (∼2530 F/g oxide, measured at 0.61 A/g in two-electrode configuration with loading active materials ∼0.16 mg/cm(2)) while maintaining excellent power density and...

Understanding the interaction between a catalyst and oxygen has been key step in designing better electrocatalysts for reduction reaction (ORR) as well applying them metal-air batteries fuel cells. Alloying studied to finely tune catalysts' electronic structures afford proper binding affinities oxygen. Herein, we synthesized noble-metal-free nanosized transition metal CuFe alloy encapsulated with graphitic carbon shell highly efficient durable electrocatalyst ORR alkaline solution....

Ionic liquid (IL) modified reduced graphene oxide (rGO–IL) nanosheets anchoring manganese (Mn3O4) are synthesized via a facile solution-based growth mechanism and applied to Zn–air battery as an effective electrocatalyst for the oxygen reduction reaction (ORR). In this study, IL moiety in these composites increases not only conductivity of system, but also electrocatalytic activity compared pristine rGO, together with synergic effect facilitating ORR intrinsic catalytic Mn3O4. Based on...

Electrocatalysts facilitating oxygen reduction reaction (ORR) are vital components in advanced fuel cells and metal-air batteries. Here we report Ketjenblack incorporated nitrogen-doped carbon sheets derived from gelatin apply these easily scalable materials as metal-free electrocatalysts for ORR. These nanosheets demonstrate highly comparable catalytic activity ORR well better durability than commercial Vulcan supported Pt catalysts alkaline media. Physico-chemical characterization...

Abstract Chemically prepared λ‐MnO 2 has not been intensively studied as a material for metal–air batteries, fuel cells, or supercapacitors because of their relatively poor electrochemical properties compared to α‐ and δ‐MnO . Herein, through the removal lithium from LiMn O 4 , highly crystalline was an efficient electrocatalyst oxygen reduction reaction (ORR). The ORR activity further improved by introducing vacancies (OVs) that could be achieved increasing calcination temperature during...

Die Tetrapodenstruktur eines Wellenbrechers diente als Inspiration für die Synthese hocheffizienten Elektrokatalysators der Sauerstoffreduktion (ORR) aus preiswertem kommerziellem Melaminschaum und dem Ruß Ketjenblack. Seine Porosität erleichtert den Stofftransport, N-dotierte Ketjenblack sowie Fe/Fe3C-funktionalisierte Gerüstoberfläche verstärken ORR-Aktivität drastisch. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such...

To date, most studies have focused only on the interaction between oxygen and catalyst, with intention of minimizing mass‐transfer resistance by using rotating disk electrode (RDE) method, which is based forced‐convection theory. begin with, in order to increase reaction rate, should be able reach active sites catalyst readily (mass transfer). Next, a moderate (i.e., not too strong or weak) (kinetics) maintained molecules allow for better adsorption desorption. Therefore, these two factors...

The advancement of hardware and software technologies makes it possible to use smartphones or Internet things for monitoring environments in realtime. In recent years, much effort has been made develop a smartphone based earthquake early warning system, where low-cost acceleration sensors inside are used capturing signals. However, because comes with powerful CPU, spacious memory, several sensors, is waste such resources only detecting earthquakes. Furthermore, mostly during the daytime,...

This research explores any potential for an on-chip cache compression which can reduce not only miss ratio but also penalty, if main memory is managed in compressed form. However, the decompression time causes a critical effect on access and variable-sized blocks tend to increase design complexity of architecture. paper suggests several techniques overhead manage efficiently include selective compression, fixed space allocation blocks, parallel decompression, use buffer, so on. Moreover...

We report metal-free electrocatalysts to enhance utilization of dissolved and gaseous oxygen during reduction reaction (ORR). Proper balance between hydrophobicity hydrophilicity is achieved using reduced graphene oxide (rGO) polyelectrolyte functionalized multiwalled carbon nanotubes (pMWNTs). In this unique architecture, both two- three-phase reactions in ORR can be maximized with a quasi-four-electron pathway.

Abstract Chemically prepared λ‐MnO 2 has not been intensively studied as a material for metal–air batteries, fuel cells, or supercapacitors because of their relatively poor electrochemical properties compared to α‐ and δ‐MnO . Herein, through the removal lithium from LiMn O 4 , highly crystalline was an efficient electrocatalyst oxygen reduction reaction (ORR). The ORR activity further improved by introducing vacancies (OVs) that could be achieved increasing calcination temperature during...