The Effect of Sodium Polymethacrylate on the Rheology of the Positive Paste and Performance of the Lead-Acid Battery

Due to its rheological properties, positive lead-acid battery paste can be difficult to spread on lead current collectors accurately and efficiently under industry machinery and setting. Sodium polymethacrylate dispersant was studied as an effective positive paste additive that could lower the yield stress of the paste without affecting paste density and battery performance. Under a four-blade vane rheometer setup, stress growth and oscillatory amplitude strain sweep experiments evaluated the rheological properties of positive paste with the addition of varying amounts of sodium polymethacrylate. Further, the electrochemical effects of sodium polymethacrylate were also evaluated in 2V batteries by testing positive active material utilization and cycle life

The Effect of Sodium Polymethacrylate on the Rheology of the Positive Paste and Performance of the Lead-Acid Battery

Due to its rheological properties, positive lead-acid battery paste can be difficult to spread on lead current collectors accurately and efficiently under industry machinery and setting. Sodium polymethacrylate dispersant was studied as an effective positive paste additive that could lower the yield stress of the paste without affecting paste density and battery performance. Under a four-blade vane rheometer setup, stress growth and oscillatory amplitude strain sweep experiments evaluated the rheological properties of positive paste with the addition of varying amounts of sodium polymethacrylate. Further, the electrochemical effects of sodium polymethacrylate were also evaluated in 2V batteries by testing positive active material utilization and cycle life

Electronic structure of fluorides: general trends for ground and excited state properties

The electronic structure of fluorite crystals are studied by means of density functional theory within the local density approximation for the exchange correlation energy. The ground-state electronic properties, which have been calculated for the cubic structures $CaF_{2}$,$SrF_{2}$, $BaF_{2}$, $CdF_{2}$, $HgF_{2}$, $\beta$-$PbF_{2}$, using a plane waves expansion of the wave functions, show good comparison with existing experimental data and previous theoretical results. The electronic density of states at the gap region for all the compounds and their energy-band structure have been calculated and compared with the existing data in the literature. General trends for the ground-state parameters, the electronic energy-bands and transition energies for all the fluorides considered are given and discussed in details. Moreover, for the first time results for $HgF_{2}$ have been presented

Fabrication of Poly(p-Phenylene)/Zeolite Composites and Their Responses Towards Ammonia

Poly(p-phenylene) (PPP) was chemically synthesized via oxidative polymerization using benzene and doped with FeCl3. The electrical conductivity response of the doped PPP (dPPP) towards CO, H2 and NH3 is investigated. dPPP shows no electrical conductivity response towards the first two gases (CO and H2), but it shows a definite negative response towards NH3. The electrical conductivity sensitivity of dPPP increases linearly with increasing NH3 concentration. To improve the sensitivity of the sensor towards NH3, ZSM-5 zeolite is added into the conductive polymer matrix. The electrical sensitivity of the sensor increases with increasing zeolite content up to 30%. The effect of the type of cation in the zeolite pores is investigated: namely, Na+, K+, NH4+ and H+. The electrical conductivity sensitivity of the composites with different cations in the zeolite can be arranged in this order: K+ < no zeolite < Na+ < NH4+ < H+. The variation in electrical sensitivity with cation type can be described in terms of the acid-base interaction, the zeolite pore size and surface area. The PPP/Zeolite composite with H+ possesses the highest electrical sensitivity of −0.36 since H+ has the highest acidity, the highest pore volume and surface area, which combine to induce a more favorable NH3 adsorption and interaction with the conductive polymer

Structural, mechanical, and electrochemical properties of Ceria doped Scandia stabilized Zirconia

The properties of Ceria doped Scandia Stabilized Zirconia (1Ce10ScSZ) nano-powder produced in Ukraine (Ukr, VMMP) are compared to the properties of commercial ones produced by Daiichi Kigenso Kagaku Kogyo (DKKK, Japan) and Praxair (USA). In comparison to DKKK and Praxair, the Ukr nano-powder demonstrated the smallest size of the particles ranging from 20 to 50 nm. The bending strength of the isostatically pressed samples made of Ukr powder was 100–120 MPa similar to that of Praxair. The bending strength of DKKK was lower (50–100 MPa) depending on the isostatic pressure. The biaxial strength of uniaxially pressed samples was the highest for DKKK (375 MPa) decreasing to 250 MPa for Ukr and 220 MPa for Praxair. Among three tested samples, the highest electric conductivity measured at 700 °C was found for Ukr electrolyte.Вивчено й порівняно властивості нанопорошків двоокису цирконію, стабілізованого двоокисами церію та скандію 1Ce10ScSZ, які виготовлено в Україні на Вільногірському державному гірничо-металургійному комбінаті (ВДГМК), в Японії компанією «Daiichi Kigenso Kagaku Kogyo» (DKKK) та в США компанією «Praxair». Порівняно з порошками виробництва DKKK та «Praxair» порошок виробництва ВДГМК (позначено як «Ukr») має найменший розмір частинок в інтервалі 20-50 нм. Міцність зразків, виготовлених із порошку «Ukr» із використанням ізостатичного пресування, становить 100-120 МПа при згині та є подібною до міцності порошку виробництва «Praxair». Міцність зразків виробництва DKKK менша (50-100 МПа) й залежить від ізостатичного тиску. Міцність одновісно пресованих зразків найвища в порошку DKKK (375 МПа), у зразках «Ukr» і «Praxair» вона становить відповідно 250 МПа та 220 МПа. Із-поміж трьох досліджених серій зразків найвищу електричну провідність при 700 °С мали електроліти, виготовлені з порошку «Ukr».Были изучены и сравнены свойства нанопорошков двуокиси циркония, стабилизированного окислами церия и скандия 1Ce10ScSZ, которые произведены в Украине на Вольногорском государственном горно-металлургическом комбинате (ВГГМК), в Японии компанией «Daiichi Kigenso Kagaku Kogyo» (DKKK) и в США компанией «Praxair». В сравнении с порошками производства DKKK и «Praxair» у порошка производства ВГГМК (обозначен как «Ukr») наименьший размер частиц в интервале 20–50 нм. Прочность образцов, изготовленных из порошка «Ukr» с использованием изостатического прессования, составляет 100–120 МПа при изгибе и подобна прочности образцов из порошка производства «Praxair». Прочность образцов из порошка DKKK меньше (50–100 МПа) и зависит от давления изостатического прессования. Прочность одноосно прессованных образцов наиболее высока (375 МПа) у порошка DKKK, в образцах «Ukr» и «Praxair» она составляет соответственно 250 МПа и 220 МПа. Из трех испытанных серий образцов самая высокая электропроводность при 700 °С была у электролитов, изготовленных из порошка «Ukr»

Resistive Oxygen Gas Sensors for Harsh Environments

Resistive oxygen sensors are an inexpensive alternative to the classical potentiometric zirconia oxygen sensor, especially for use in harsh environments and at temperatures of several hundred °C or even higher. This device-oriented paper gives a historical overview on the development of these sensor materials. It focuses especially on approaches to obtain a temperature independent behavior. It is shown that although in the past 40 years there have always been several research groups working concurrently with resistive oxygen sensors, novel ideas continue to emerge today with respect to improvements of the sensor response time, the temperature dependence, the long-term stability or the manufacture of the devices themselves using novel techniques for the sensitive films. Materials that are the focus of this review are metal oxides; especially titania, titanates, and ceria-based formulations