Total Lab Supplies - Everything for your laboratory

Total Lab Supplies - Everything for your laboratory
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Showing posts with label electrodes. Show all posts
Showing posts with label electrodes. Show all posts

Tuesday, 22 November 2016

Why Lithium-ion Batteries Catch Fire

Why have some of Samsung’s phones been catching fire? Check out the infographic below to find out.

Source: Compound Interest 

So, who invented the lithium battery? 

Lithium batteries were proposed by M Stanley Whittingham, now at Binghamton University, while working for Exxon in the 1970s. Whittingham used titanium(IV) sulfide and lithium metal as the electrodes. However, this rechargeable lithium battery could never be made practical. Titanium disulfide was a poor choice, since it has to be synthesized under completely sealed conditions. This is extremely expensive (it cost $1000 per kilo for titanium disulfide raw material in the 1970s).

When exposed to air, titanium disulfide reacts to form hydrogen sulfide compounds, which have an unpleasant odour. For this, and other reasons, Exxon discontinued development of Whittingham's lithium-titanium disulfide battery. Batteries with metallic lithium electrodes presented safety issues, as lithium is a highly reactive element; it burns in normal atmospheric conditions because of the presence of water and oxygen. As a result, research moved to develop batteries where, instead of metallic lithium, only lithium compounds are present, being capable of accepting and releasing lithium ions.

Reversible intercalation in graphite and intercalation into cathodic oxides was discovered in the 1970s by J. O. Besenhard at TU Munich. Besenhard proposed its application in lithium cells. Electrolyte decomposition and solvent co-intercalation into graphite were severe early drawbacks for battery life.

There were two main trends in the research and development of electrode materials for lithium ion rechargeable batteries. One was the approach from the field of electrochemistry centering on graphite intercalation compounds, and the other was the approach from the field of new nano-carbonaceous materials.

History described above is based on the former stand point. On the other hand, in the recent interview article concerning the first stage of scientific research activity directly related to the LIB developments, it is stated that looking at the major streams in research development, the negative-electrode of today’s lithium ion rechargeable battery has its origins in PAS (polyacenic semiconductive material) discovered by Professor Tokio Yamabe and later Shjzukuni Yata at the beginning of 1980’s. The seed of this technology, furthermore, was the discovery of conductive polymers by Professor Hideki Shirakawa and his group, and it could also be seen as having started from the polyacetylene lithium ion battery developed by MacDiarmid and Heeger et al.

For more information visit:-

Friday, 13 December 2013

Measuring Conductivity

The conductivity (or specific conductance) of an electrolyte solution is a measure of its ability to conduct electricity. The SI unit of conductivity is siemens per meter (S/m).

Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring the ionic content in a solution. For example, the measurement of product conductivity is a typical way to monitor and continuously trend the performance of water purification systems.

In many cases, conductivity is linked directly to the total dissolved solids (T.D.S.). High quality deionised water has a conductivity of about 5.5 μS/m, typical drinking water in the range of 5-50 mS/m, while sea water about 5 S/m (i.e., sea water's conductivity is one million times higher than that of deionised water)

Conductivity Meters - Two electrodes with an applied AC voltage are placed in the solution. This creates a current dependent upon the conductive nature of the solution. The meter reads this current and displays in either conductivity (EC) or ppm (TDS).

Our two part guide will help you to measure conductivity accurately.  The guides answer the 7 most asked questions regarding conductivity and the second part is a comprehensive guide on theory and measurement.

Just click on the links below to download your copies.

Part 1 - http://www.prlabs.co.uk/news/article.php?Id=232
Part 2 - http://www.prlabs.co.uk/news/article.php?Id=233