Search

Field emission (FE) devices are advanced lighting devices that have a 2-D planar configuration, different from the 0-D (dot) and 1-D (line) configurations of light-emitting diode (LED) and fluorescent lighting, respectively. The purpose of this study is to develop a FE lighting device with a lateral-cathode triode. Carbon nanotubes (CNTs) are used as emitters and ZnS particles are used as a green phosphor. The materials were screen-printed onto two soda lime glass substrates. To increase the device lifetime and performance, we applied pulsewidth modulation (PWM) to the gate electrode. A high luminance of 12 690 cd/m2 and a good luminance uniformity of 84% were achieved for a lighting device with a lateral-cathode structure. [ABSTRACT FROM AUTHOR]

A double-sided light source based on field emission (FE) using an alternating current (ac) power source is demonstrated. Electrode plates acted as cathode or anode consisting an indium tin oxide glass, a screen-printed ZnS phosphor layer and urchin-like \alpha\-Fe2O3 emitters coated on the layer. Two pieces of the plates were assembled together with the coated surfaces facing each other to make a parallel-plate, diode-structure FE device with a gap distance of 300 \mum. The 1-cm^2 device shows a double-sided luminance distribution with a turn-on field of 2.2 V/\mum, 90.23% uniformity and a maximum luminance of 8750 cd/m^2 at 2 kV. The novel structure and ac model operation provide a double-sided luminance, high brightness, antiarcing, good thermal management, and long lifetime. [ABSTRACT FROM PUBLISHER]

The inhibitive effects of functional groups originating from the presence of additives on corrosion are linked to the physicochemical and electronic properties of these surficial chemical species. In this work, the acetoxy group (i.e. weak bases) with different orbital characters is integrated with donating/accepting molecules which reveals dissimilar inhibitive behaviour. Introducing cations on the acetoxy groups (-Ac) as additives leads to mitigation of undesirable self-corrosion of the anode. The Al-air battery corresponded to a maximum capacity of 2817 mAhg−1 at 10 mAcm−2 with the use of barium-Ac/KOH electrolyte, demonstrates nearly 95% of the theoretical capacity. However, a capacity of only 2392 mAhg−1 is observed for free additive. In addition, the maximum power density (i.e. 91.32 mWcm−2) increased by nearly 50% with the employment of barium-Ac/KOH. The rechargeable Al–air battery based on barium-Ac/KOH presents a low voltage gap of 0.83 V with a remarkable cyclic stability of 25,000 s. The results show that the acetoxy group integrated with metal ions can be a key player in reducing H 2 evolution rate in the aluminium-air batteries. XPS analysis confirmed an Al-complex (i.e. Al-acetoxy) is formed using barium-ac. DFT calculations confirmed that barium-Ac/KOH provides the minimum value of ΔE (about 5.4 eV), indicating the remarkable ability for reacting with Al+3 ions to adsorb on the anode surface leading to complex (Ba-Ac-Al3+) formation. This study highlights the parasitic corrosion reaction leading to low coulombic efficiency in rechargeable Al- air batteries. • The impacts of additive integrated with acetoxy group was studied on Al corrosion and H2 evolution. • The corrosion inhibition efficiency follows the order of: Ba-acetoxy > Ca-acetoxy > Ethyl-acetoxy. • Ba–Ac/KOH exhibited the optimum discharge capacity 2817 mAh/g and 95% Al utilization. • XPS results revealed a complex containing Al-acetoxy contribute to reduce Al self-corrosion. [ABSTRACT FROM AUTHOR]

Urchin-like α-Fe 2 O 3 microspheres (radial α-Fe 2 O 3 nanowires on α-Fe 2 O 3 microspheres) are used as field emitters for a flat-panel lighting device with a lateral-gate-electrode structure. The urchin-like α-Fe 2 O 3 microspheres are in situ grown on the cathode electrode via thermal oxidation at 350 °C for 12 h after the screen-printing of pattern Fe microspheres on the cathode electrode. The lateral-gate triode structure comprises an Ag cathode and a pair of Ag gate electrodes screen-printed laterally on both sides of the cathode. The role of the gate electrodes is to enhance the emission current and increase luminance uniformity and that of the anode electrode is to control the luminance intensity. The radial nanowire emitters on the spheres ensure good field emission performance without any pretreatment and in situ growth of the material enhances the contact between the electrode and the material. The microspheric emitters and the lateral-gate structure, which covers a small part (4.32%) of the printed area over the entire panel (3.5 cm × 5 cm) leads to, high luminance, excellent luminance uniformity and tunable luminance characteristics of the field-emission light source. A maximum luminance of 8330 cd/m 2 and a luminance uniformity of 92.4% are achieved with a gate voltage of 500 V, an anode voltage of 4000 V, and the anode current of 1.32 mA. [ABSTRACT FROM AUTHOR]

• Development of lithium metal based anode through novel Semi-infusion technique. • Ni mesh to be act as a host material to accommodate li ions during stripping/plating. • The symmetrical Li/SnO 2 -Ni cell revealed a low voltage gap of ∼ 8 mV over 2000 h at 1 mA cmˉ2 and 1 mAh cmˉ2. • Full cell cycling performance of the Li/SnO 2 -Ni with LFP delivered a specific capacity of 170 mAh gˉ1 with an excellent stability. Lithium metal battery is a promising candidate for the next generation batteries due to its high theoretical specific capacity and energy density. However, the dendritic propensity of Li metal and inevitable volume variation are critical obstacles for commercialization. Here, we prepare a novel anode that Li infused partially into the tin oxide coated Ni mesh (Li/SnO 2 -Ni) by semi-infusion strategy. The strategy can provide an adequate but not excessive amount of Li in the host for the battery. The SnO 2 -Ni mesh abates the dendritic formation and volume variation due to its lithiophilic property, three-dimensional (3-D) structure, and excellent conductivity guiding the Li-ion deposition and stripping uniformly during cycling. As a result, Li/SnO 2 -Ni cell can cycle a long span with an exceptionally low voltage gap of 8, 15, and 200 mV at a different current density and of 1, 3, and 35 mA cm−2, and a capacity of 1, 1 and 5 mAh cm−2, respectively, in a symmetrical cell. The performance of full cell against LiFePO 4 cathode achieves a superior capacity of 173 mAh g−1 at 0.2 C and the retention of 90 % after 70 cycles. This work offers a facile and effective strategy to fabricate a 3-D composite anode and promotes the practical applications of Li metal batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

• Development of lithium-metal-based anodes based on Li infusion technique is reviewed. • Several three-dimensional substrates designed to withhold molten Li are discussed. • The roles of porosity, lithiophilicity, and conductivity for anodes are discussed. • Unsolved issues and further research considerations are summarized. Lithium-metal-based anodes (LMA) are known to be most propitious for high-energy rechargeable batteries owing to their extremely high theoretical specific capacity (3860 mAh/g) and low electrode potential. Despite this, uncontrollable dendrite growth and large volume change are regarded as the main barriers to their commercialization. Various approaches for anode modification have been proposed to overcome these barriers. Unfortunately, the formation of short filamentous dendrites with various morphologies is still a problem to be addressed. For constructing stable anodes, lithium infusion is considered to be the most efficient strategy for confining the growth of dendrites and volume change. In this review, we dedicate recent advancements in a variety of porous substrates and their impacts on lithium infusion. We firmly believe that this review could dispense an effective facet for mitigating the mentioned issues and excel the superior performances. [ABSTRACT FROM AUTHOR]

Silicon is regarded as one of the most promising anode materials for high performance lithium-ion battery (LIB) due to its high theoretical specific capacity. However, the low electrical conductivity and the severe volume change during charging and discharging process result in poor cyclic performance. In this study, a low cost, high-purity silicon powder from the sawing waste in photovoltaic industry was used as the active material. Pitch from petroleum residue was used as carbon source to provide a good conductive pathway and prevent the drastic volume changes of Si. The pitch-based silicon-carbon composites with a porous structure were fabricated by electrospraying technique followed by a sequence of thermal processes. The results of the charge/discharge showed that the 100th charge capacity of 1515 mAh/g at 0.2 C with the retention of 73.95% while the 200th charge capacity of 929 mAh/g at 0.5 C with the retention of 70.61% (Pitch-Si-0.5) can be obtained. On the other hand, the sample with medium content of Si showed charge capacity of 522 mAh/g at 0.5 C with the extremely high retention of 94.99% after 200 cycles. The rate capability indicated that the soft carbon derived from pitch provided a good rate capability because of its amorphous structure. We demonstrated that industrial wastes can form a superior anode material for LIB application. • Spherical silicon-carbon composite was formed as an anode material for LIB. • Silicon was from the waste of the photovoltaic industry and the source of the carbon is petroleum pitch. • The composite demonstrated an excellent capacity and stability (1515 mAh/g at 0.2C, 73.95% retention at 200th cycle). [ABSTRACT FROM AUTHOR]