Daniell Cell Research Articles

Re-building Daniell cell with a Li-ion exchange film.

Daniell cell (i.e. Zn-Cu battery) is widely used in chemistry curricula to illustrate how batteries work, although it has been supplanted in the late 19th century by more modern battery designs because of Cu2+-crossover-induced self-discharge and un-rechargeable characteristic. Herein, it is re-built by using a ceramic Li-ion exchange film to separate Cu and Zn electrodes for preventing Cu2+-crossover between two electrodes. The re-built Zn-Cu battery can be cycled for 150 times without capacity attenuation and self-discharge, and displays a theoretical energy density of 68.3 Wh kg−1. It is more important that both electrodes of the battery are renewable, reusable, low toxicity and environmentally friendly. Owing to these advantages mentioned above, the re-built Daniell cell can be considered as a promising and green stationary power source for large-scale energy storage.

The Daniell cell, Ohm's law, and the emergence of the International System of Units

Telegraphy originated in the 1830s and 40 s and flourished in the following decades but with a patchwork of electrical standards. Electromotive force was for the most part measured in units of the predominant Daniell cell, but each telegraphy company had their own resistance standard. In 1862, the British Association for the Advancement of Science formed a committee to address this situation. By 1873, they had given definition to the electromagnetic system of units (emu) and defined the practical units of the ohm as 109 emu units of resistance and the volt as 108 emu units of electromotive force. These recommendations were ratified and expanded upon in a series of international congresses held between 1881 and 1904. A proposal by Giovanni Giorgi in 1901 took advantage of a coincidence between the conversion of the units of energy in the emu system (the erg) and in the practical system (the Joule). As it was, the same conversion factor existed between the cgs based emu system and a theretofore undefined MKS system. By introducing another unit X (where X could be any of the practical electrical units), Giorgi demonstrated that a self-consistent MKSX system was tenable without the need for multiplying factors. Ultimately, the ampere was selected as the fourth unit. It took nearly 60 years, but in 1960, Giorgi's proposal was incorporated as the core of the newly inaugurated International System of Units (SI). This article surveys the physics, physicists, and events that contributed to those developments.

Students' Misunderstanding of Teaching Metaphors : Understanding the Transfer of Electrons in a Daniell's Cell

Students' Misunderstanding of Teaching Metaphors : Understanding the Transfer of Electrons in a Daniell's Cell

Molecular Genetics of Bacteria. Third Edition. By Larry Snyder and Wendy Champness. Washington (DC): ASM Press. $109.95. xvii + 735 p; ill.; index. ISBN: 978-1-55581-399-4. 2007.

Previous articleNext article No AccessNew Biological BooksMolecular Genetics of Bacteria. Third Edition. By Larry Snyder and Wendy Champness. Washington (DC): ASM Press. $109.95. xvii + 735 p; ill.; index. ISBN: 978-1-55581-399-4. 2007.Daniel GageDaniel GageMolecular & Cell Biology, University of Connecticut, Storrs, Connecticut Search for more articles by this author PDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 83, Number 1March 2008 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/586948 Views: 70Total views on this site © 2008 by The University of Chicago. All rights reserved.PDF download Crossref reports no articles citing this article.

A new flow-type cell by the application of magnetic microfluidic chip

Using a magnetically formed channel called a magnetic channel, a new flow-type cell is proposed. The magnetic channel consists of magnetic walls that are formed by heterogeneous distributions of magnetic flux density around a ferromagnetic track under a magnetic field. The magnetic wall separates the paramagnetic oxidant solution from the diamagnetic reductant solution at a liquid–liquid interface without any solid membranes. In the magnetic channel formed on the cathode, the oxidant solution flows in a quasi-frictionless mode. The anode is placed in the reductant solution surrounding the magnetic channel. Such a geometrical configuration between the oxidant and reductant solutions is interchangeable depending on the magnetism of the solutions. To examine this concept, a Daniel cell system was adopted, where the copper ion in copper sulfate solution is employed as the oxidant and the zinc atom of zinc electrode as the reductant. The copper ion is paramagnetic, so that 1 mol dm−3 copper sulfate solution is injected into the magnetic channel formed on the copper cathode. Zinc sulfate solution (1 mol dm−3; diamagnetic) together with the zinc anode are placed surrounding the magnetic channel. The performance of this flow-type battery was examined up to a current density of 22 mA cm−2.

A Historical Analysis of the Daniell Cell and Electrochemistry Teaching in French and Tunisian Textbooks

French textbooks from 1840 to the last reform and three recent Tunisian textbooks were studied to analyze how electrochemistry, and particularly the Daniell cell, was presented to students in secondary school. The technical and historical importance of the Daniell cell induced curriculum designers to introduce it very early in the chemistry sequence. However, due to progress in the understanding of redox reactions, emphasis was finally put on half reactions involving only one redox couple. As a consequence, a teaching model of the Daniell cell consisting of two half-cells separated by a salt bridge, different from any Daniell cell ever built in history, invaded French and Tunisian textbooks. Analysis of several important studies on students' misconceptions in electrochemistry shows that students have trouble in understanding ionic conduction and the structure of solutions. In this context, the separation between the two solutions and the presence of the salt bridge, although useful for presenting redox re...

Electrochemical Oscillation in Daniell Cell Induced by Emulsion

Electrochemical Oscillation in Daniell Cell Induced by Emulsion

고등학교 화학 교과서에 기술된 볼타 전지의 오개념을 줄이기 위한 실험 장치 개발

볼타 전지에 대한 학생들의 오개념과 고등학교 화학 2 교과서에서 기술된 내용을 연구, 분석하였다. 볼타 전지에 대해 많은 학생들이 오개념을 가지고 있으며 몇몇 화학교과서의 경우 내용이 잘못 기술되어 있다는 것을 본 연구에서 밝혔다. 대부분의 교과서에는 볼타 전지의 초기 측정 전압이 왜 1.1V와 유사하며 시간이 지남에 따라 감소하는지에 대한 명확한 설명이 없다. 표준상태에서 볼타 전지의 기전력은 0.76V 이지만 어떤 교과서에는 다니엘 전지처럼 1.1V로 기술되어 있다. 대부분의 학생들은 볼타 전지를 배우거나 실험을 한 후에도 여전히 오개념을 가지고 있으며 이것은 적어도 다음 두 가지 요인에서 기인된다고 여겨진다. 첫째, 볼타 전지의 초기 측정 전위값이 다니엘 전지의 전위와 매우 유사하기 때문에 학생들이 혼동하여 오개념을 가진다. 둘째, 대부분 교과서의 볼타 전지 실험은 표준 상태가 아닌 조건에서 수행되도록 기술되어 있으므로 학생들이 실험을 하더라도 표준 상태 기전력값을 얻을 수 없기 때문에 여전히 오개념을 가지게 된다. 따라서 우리는 학생들의 오개념을 줄일 수 있는 개선된 볼타 전지의 실험 모형을 제안하였다. Misconceptions of students for a Voltaic cell were studied and their contents described in the high school chemistry II textbooks were analyzed. This study shows that students have many misconceptions and a few of chemistry textbooks contain some false description in a Voltaic cell. In the most textbooks, the reasons why the measured cell voltage of a Voltaic cell is near 1.1 V at the initial stage and then it decreases with time are not explained clearly. The emf of a Voltaic cell at a standard state is 0.76 V but in some textbooks it is described as 1.1 V of a Daniel cell. Even after learning the Voltaic cell or performing the experiment of textbooks, most students still have some misconceptions. These may be due to at least two following facts: the first is that the measured cell voltage of a Voltaic cell at the initial stage is very similar to that of a Daniel cell. The second is that the most experiment of a Voltaic cell is not performed under the condition of a standard state. Therefore, we have suggested a model of the modified experimental setup of a Voltaic cell that could reduce misconceptions of students.

중·고등학교 과학 교과서에 제시된 볼타전지에 대한 문제점 분석

The purpose of this study was to improve the problems of the voltaic cell described in the science textbooks of secondary schools. For this purpose, the contents of science textbooks which are related to the voltaic cell were analyzed and the problems which were not explained clearly by theorems were tried to be explained by experiments, and lastly sug- gestions were made toward the improvements regarding the voltaic cell in the science textbooks. The findings are that there are problems on the ways of ensuring whether the voltaic cell operates properly as a chemical battery, on the explanation of why the hydrogen bubbles form at the zinc electrode, on the cell potential, on the unification of the electrode terminology used, and on the mention of the current. Solutions to the problems except the cell potential were suggested. According to the experiment, the theoretical potential was calculated by considering the potentials of redox reactions at the two electrodes of the cell and by taking into account the characteristics of the electrodes such as the work function, ionization energy, stan - dard reduction potential, and electronegativity. The cell potential of the voltaic cell is explained by several factors. In the improved version of the textbook's introduction section to the voltaic cell, it is necessary to describe the voltaic cell his- torically. For the conceptual section, it should be explained in terms of the Daniel cell.

The first stimulators-reviewing the history of electrical stimulation and the devices crucial to its development

The following topics are discussed: the capacitor-discharge stimulator; empirical strength-duration curve; theoretical strength-duration curve; basis for stimulation; galvanic (direct-current) stimulation; Daniell cell; Grove (Bunsen) cell; Leclanche cell; interrupted direct-current stimulators; the inductorium; Galvanic-Faradic stimuli to diagnose nerve injury; modern stimulators.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Why the Daniell cell works!

The strength of bonds between atoms in metals, the relative ease of removing electrons from atoms, and the energy lowering of the attraction of water molecules for positive ions in solution all aid beginning student's understanding of why reactions occur.

Performance characteristics of galvanic cells employing packed-bed electrodes and a static electrolyte

The polarization of a Daniell cell with an unstirred electrolyte and packed-bed copper and zinc electrodes was measured for different bed heights, particle sizes and temperatures. A comparison between the performance of a cell with plane electrodes and that of a cell with packed-bed electrodes shows that the output power is increased by a factor ranging from 2 to 16 depending on the operating conditions of the cell with packed-bed electrodes. The degree of polarization decreases with decreasing bed height and with increasing particle size and temperature.

Samuel Taylor Coleridge and the appointment of J. F. Daniell, F. R. S., as Professor of Chemistry at King’s College London

IN the autumn of 1831 King’s College, London, opened its doors to the first group of students. The range of subjects in which instruction was offered included chemistry, and the Professor of Chemistry, who gave his Inaugural Lecture on n October, was J. F. Daniell, F. R. S., subsequently the inventor of the Daniell cell. Before 1831 Daniell’s most original work had been concerned with meteorology and with the construction of an instrument for measuring atmospheric moisture, the Daniell hygrometer. An essay of his during this period, on ‘Artificial Climate’, drew attention to the importance of atmospheric humidity and revolutionized the management of greenhouses: he was awarded the silver medal of the Horticultural Society in recognition of this contribution. By comparison, Daniell’s early work in chemistry had had less impact, and it is thus of interest to enquire by what procedure he came to be selected by the Council of King’s College for appointment to the chair of chemistry.

From the Daniell cell to the apparatus kit

From the Daniell cell to the apparatus kit

Transmission and supply voltages

The origin of the volt goes back to the early days of electrochemistry, when the Daniell cell was accepted as the first basic unit of electromotive force. In this historical account, the author traces how power-supply and transmission-system voltages have changed and increased as technology and load demands advanced.

Electrochemical and Related Phenomena under Weightless Conditions: I . Flowing Electrolyte Thermocells

A flowing electrolyte thermogalvanic cell (Cu, ) has been studied under weightless conditions via drop‐tower experiments. Unexplained perturbations have been observed in the output potential in both the time‐dependent (emf build‐up) and quasi‐stationary state regions over a wide range of experimental conditions. Exhaustive control experiments as well as the general and over‐all reproducibility of perturbations per se in a large number of trials rule out oscillations in the hydraulic system as well as random transients as factors responsible for the observed phenomena. Stationary electrolyte systems including thermocells, concentration cells, and a Daniell cell, exhibited similar perturbations during the transition.The addition of urea was found to dampen the marked oscillations normally shown by a copper thermocell at the same output potential. The result is important in view of the known decreased ultrasonic attenuation and increased sound velocity caused by urea addition to water. At ambient temperatures the electrolytic conductivity of freshly prepared urea‐cupric sulfate solutions gradually increases and in subsequent drops the zero‐gravity induced oscillations reappear.Copper thermocells utilizing nonaqueous solvents (acetonitrile or absolute methanol) exhibit a voltage decrease (several millivolts) but the time/potential curve continues on its original course after impact. The potential of concentration cells (with linear and nonlinear gradients) increases (several millivolts in 0.7 sec), then decays to its initial value prior to impact; cells with linear gradients exhibit relatively larger changes. Inversion tests are also described. Daniell cells (1.09v at 20°C) show a similar behavior except that the voltage increase is about 40 mv.To understand better the influence of the transition on physico‐chemical processes, the electrochemical measurements were supplemented (with the appropriate controls) by a study of diffusional phenomena, heterogeneous and homogeneous chemical reactions. In all cases increased rates were observed and are attributed to enhanced ion mobility during weightlessness. On the basis of these experiments it must be concluded that an interaction exists between chemically reacting systems and gravitational fields.

The Electromotive-force and the Change of Inner State of the Daniell Cell

The Electromotive-force and the Change of Inner State of the Daniell Cell

Prof. Johannes Bosscha

THE career of this eminent physicist has not only been of importance for the advancement of physics, but also of the greatest benefit to the development of exact science in Holland. Born on November 18, 1831, at Breda, Bosscha was initiated in physics by van der Willigen, and entered the University of Leiden in 1850. His eminence as a student in different respects foreshadowed the leading position he occupied in later life. In Bosscha's later observational work the influence of the great astronomer Kaiser is evident. In March, 1852, he took his degree with a dissertation on the differential galvanometer, worked out in the Physical Laboratory at Leiden, then under the direction of Rijke. After a short stay at Berlin, he returned to this laboratory as assistant. Attention was soon directed to him by the vigorous part he took in the great scientific movement in connection with the law of conservation of energy. The most important problem dealt with in his well-known papers on the mechanical theory of electrolysis is the test of Kelvin's calculation of the electromotive force of a galvanic cell from the heat developed by the chemical processes which accompany the current. By determining in absolute measure the electromotive torce of the Daniell cell, he contributed to the work which ultimately led to the adoption of the C.G.S. system of electrical units. He gave a solution of multiplex telegraphy, and several rules and methods introduced by him have passed through the text-books into the electrotechnic practice.

3. On Transition-Resistance and Polarisation

In a paper communicated to this Society last Session, I gave an empirical formula representing the relation between current-strength and time when platinum plates are used for the passage of a current through acidulated -water, the electromotive force being that of a single Daniell cell. As is well known, we can look upon the electrodes as condensers of very great capacity.

On a Constant Daniell Cell, for use as a Standard of Electromotive Force

On a Constant Daniell Cell, for use as a Standard of Electromotive Force