Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electronic life extension

30.08.2006
A new electrode for lithium rechargeable batteries

Everyone knows the frustration of battery discharge: that sinking feeling when your notebook computer shuts down before you've saved that vital document or the artistic annoyance when your digital camera cannot snap that last holiday sunset. Worse still, what about those times when you're stuck on a five-hour flight with only a minute's worth of charge in your mp3 player?

A solid solution to the problem could come from chemists in the UK. They have devised a new and efficient way to improve battery power as well as make that precious charge last longer. They describe their results in the latest issue of Advanced Materials.

Modern rechargeable batteries for electronic gadgets generally use lithium compounds as the positive electrode and have revolutionized the electronics industry. They can be made very compact but can still deliver the required voltage to run everything from cell phones to digital cameras and notebook computers. And, not forgetting those ubiquitous mp3 players.

As gadgetry becomes sophisticated so consumer demands on battery life have risen. Moreover, more powerful lithium batteries are beginning to be used in power tools and may soon be seen in electric vehicles, applications that are much more draining than those for which conventional lithium batteries are used.

Now, Kuthanapillil Shaju and Peter Bruce of the University of St Andrews, Scotland, explain how lithium batteries use so-called intercalation materials as their anode. These materials are composed of a solid network of lithium atoms together with other metals, such as cobalt, nickel, or manganese, meshed together with oxygen atoms. When you charge a lithium battery, the charging current pulls the positive lithium ions out of this network. Then, when you use the battery, it discharges as these lithium ions migrate back into the electrode, pulling electrons as they go, and so generating a current.

The challenge is to make new electrode materials that deliver high power (fast discharge) and high energy storage. Shaju and Bruce hoped they could solve these problems by developing a new way of synthesizing a particular lithium intercalation compound (Li(Co1/3 Ni1/3 Mn1/3)O2). As a bonus, they hoped to be able to simplify the complicated manufacturing process.

The St Andrews team devised a new synthetic approach to the compound that involves simply mixing the necessary precursor compounds - organic salts of the individual metals - with a solvent in a single step. This is in sharp contrast to the conventional multi-step process used for making the compound. Using this technique, they were able to make highly uniform lithium oxide intercalation materials in which nickel, cobalt, and manganese ions are embedded at regular intervals in the solid, which also contains pores for the electrolyte.

The highly porous nature of the new material is crucial to its electrical properties. The pores allow the electrolyte to make intimate contact with the electrode surface resulting in high rates of discharge and high energy storage. The St Andrews team has tested their new lithium electrode material by incorporating it into a prototype battery and found that it gives the battery far superior power and charge retention. Increasing the rate by 1000%, so that the battery can be discharged in just six minutes, reduces the discharge capacity by only 12%. The test results suggest that this approach to rechargeable batteries could be used to make even higher power batteries for vehicles and power tools. Most importantly though, the new lithium materials could mean an end to mp3 player power loss on that long-haul flight. (Assuming you remembered to charge it up in the first place.)

There's an added bonus in that replacing a proportion of the cobalt used in the traditional lithium-cobalt-oxide electrodes with manganese improves safety by reducing the risk of overheating.

Author: Peter G. Bruce, University of St. Andrews (UK), http://chemistry.st-and.ac.uk/staff/pgb/group/

Title: Macroporous Li(Ni1/3Co1/3Mn1/3)O2: A High-Power and High-Energy Cathode for Rechargeable Lithium Batteries

Advanced Materials 2006, 18, No. 17, 2330–2334, doi: 10.1002/adma.200600958

| Advanced Materials
Further information:
http://chemistry.st-and.ac.uk/staff/pgb/group/

More articles from Power and Electrical Engineering:

nachricht Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University

nachricht TU Graz researchers show that enzyme function inhibits battery ageing
21.03.2017 | Technische Universität Graz

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>