Battery Technology Leads The Way

Rechargeable batteries are having to keep up with the pace being set by the mobile comms revolution. “No chemical reaction is 100 per cent reversible,” says Tony Gozdz, chief scientist at US firm Telcordia Technologies. This may be true but rechargable lithium ion (Liion) batteries – as used in portable computers, mobile phones & electronic cigarettes – make a pretty good stab at it, although there can be complications.

The accepted performance metric for rechargable batteries is that after 500 recharging cycles, the overall dip in performance is less than 20 per cent. “For each cycle this equates to a reversibility of 99.96 per cent – an incredibly small degree of degradation,” says Gozdz.Battery Tech

As head of battery R&D at Telcordia, formeriy Bellcore, improving battery technology is a topic close to Gozdz’s heart. What occupies him, and many other scientists at companies like Sony, Sanyo, Panasonic, Toshiba and Philips, are ways to squeeze Liion technology into ever slimmer packages. Liion is the predominant technology used in laptops. Being packed in cylindrical metal cases provides the necessary uniform pressure to hold the battery’s electrochemical materials together.

The drawback of the cylindrical shape is the space it takes up, especially when several are placed in series to achieve the 11 to 15V needed by notebooks. In turn, more than one bank is required to achieve an acceptable operating life. Overall a quarter of the overall volume is wasted. The development of fiat battery technology means there is more battery per unit volume. Refine the battery thickness and further possibilities arise.

Thomas & Betts, a licensee of Telcordia’s plastic Liion technology (Plion), is working on a large fiat battery to be placed behind a notebook’s screen. Placing it there not only results in a greater overall capacity, it also separates it from local hot-spots such as the PC’s microprocessor.

Mobile handsets, in contrast, embrace three battery types, each at a different stage in their evolution: nickel metal hydride (NiMH), Liion and Liion solid-polymer (lithium-polymer). Telcordia’s Plion is an example of the latter.

NiMH is the most mature and cheapest of the three. It also has the advantage of not needing any protection circuitry. For this reason NiMH AAA cells still claim the largest share of the European mobile phone market.

In Japan, the situation is different, says Daiichiro Eguchi, senior manager at Toshiba’s battery division. With Japan’s appetite for petite handsets – some 8mm thick and weighing as little as 55g – slimmer, lighter batteries are required. This is why battery makers are embracing Liion battery systems.imagebattery

What Liion offers is a battery thickness down to 4mm. “It is very difficult to make Liion batteries below 4mm,” said Eguchi.

Typically a metal can is used to bind the internal electrodes and separator material. Although the can’s 0.6mm wall thickness sounds insignificant, when the battery is only 4mm, both walls – each 0.6mm – account for a significant proportion of the battery’s volume. Enter lithium-polymer. It is based on the same electrochemical active components as Liion, where it differs is in the battery’s construction.

It promises lightweight batteries with a thickness down to 1mm, enclosed in a thin aluminium bag. “Like a coffee bag,” says Gozdz. The aluminium sheath prevents chemical solvent leaking out and water vapour getting in, which degrades the battery.

Panasonic manufactures lithium-polymer technologies for mobile phone and portable computers. Stephen Evangelou, Panasonic’s battery sales group’s technical manager, says the company has already produced lithium polymer in limited volumes for mobile handsets. Volume production is expected by April next year.

Toshiba is another company developing lithium polymer technology. According to Eguchi, Toshiba is not close to releasing product. “We will wait one or two years,” says Eguchi, who admits that Toshiba is still having problems achieving the performance required at low temperatures. Meanwhile Toshiba is launching an advanced Liion battery which while using a gel, has a different chemical composition to lithium-polymer.

Philips, while not a battery manufacturer, is also investigating lithium-polymer battery technology at its Research Laboratories in Eindhoven. “It’s something we need to know about,” explained Dr. Hans Feil, general manager of Philips Lithylene. What Philips Research has done is develop a lithium-polymer manufacturing process which it claims extends the battery’s capacity.

Dubbed lithylene, the process uses rivets instead of a can to give the structure rigidity. Micro-holes are introduced into the electrodes and separator. These are then filled with polymer, which, when set, binds together the battery’s materials.battery-620x448

A prototype battery has already been demonstrated by Philips Research. Feil claims the lithylene battery will deliver 800mAh, while competitor batteries with the same volume offer only 600mAh. The battery form factor for the latest mobile phones is 62 x 35 x 3.6mm. Toshiba’s advanced Liion battery, to be launched next February, will deliver 610mA while Panasonic’s lithium-polymer battery of the same dimension will offer 550mAh.

Telcordia’s Plion technology uses a “totally different” manufacturing process to that of Philips’. It binds the layers together without the need for rivets. Gozdz claims that this aids the manufacturing process. The company has licensed its Plion battery technology to several companies, four of which have already been announced.

Philips is also making its lithylene technology available for licensing. “We haven’t licensed The technology yet but we already have some very serious candidates,” said Feil. The challenge facing all the companies pursuing lithium polymer is to make the manufacturing process reliable. It is not a technology or electrochemical issue, but rather the optimisation of equipment for volume manufacturing and its debugging, says Gozdz.

As he points out: “It took seven to eight years and hundreds of millions of cells to get lithium ion to the point where it was right.”

The Internet – How We Got Here

Posted on June 23, 2014 in Internet

The Internet is a network of computers that allows users at various locations to exchange information with one another. It consists of hundreds of millions of computers in over 100 countries. Not operated by any one business or government, although heavily censored by governments in countries such as China, it is a cooperative venture in which many companies, organizations, and individuals choose to participate by making their computers part of the network.

The Internet

The Internet’s beginnings are traceable to a project called ARPAnet that was begun in the 1960s by the U.S. Department of Defense. Government and academic researchers collaborated to develop computer-to-computer communications using a new technology called packet switching. Packet switching is a means for chopping data into a series of data packets or chunks–like breaking up a long letter into individual pages and sending each one separately. Each packet is like a letter with “to” and “from” address labels. Packets are passed along by computers in the network until they reach their destination and are reassembled. Each packet might take a different path through the network to its destination, bypassing areas that are damaged or temporarily in use for other transmissions.

Each computer connected to a TCP/IP network has a unique internet protocol (IP) address. This is a numerical address (such as 140.147.248.209) that other computers use to identify it. In 1984, domain names were introduced to make the network more user-friendly. A domain name (such as uscongress.gov) is the word equivalent of an IP address. A network device called a domain name server converts domain names to IP addresses. In 2010, computer network experts warned of a looming shortage of unique Internet Protocol (IP) addresses that could strangle Internet traffic in 2011. For companies in the United States, IP addresses are parceled out by the American Registry for Internet Numbers (ARIN). Robust Internet growth, especially with the numbers of attached devices (each requiring a unique IP address when online) means that by the end of 2010, less than 1 out 20 IP addresses remain available for assignment.

E-mail (electronic mail) was developed in the early 1970s and went on to become one of the most popular uses of the Internet. Other applications that are widely used include file transfer, real-time broadcasting and communications (including chat rooms), electronic bulletin boards, newsgroups, and game-playing. Each of these applications has a protocol or agreed-upon set of rules for data transfer that allows it to take place. The World Wide Web makes all of these applications accessible through one interface, which is provided by a Web browser such as Explorer or Safari.

In August 2010, sociology and communication researchers at both the Swiss Federal Institute of Technology in Lausanne and Cornell University released analysis of a study of online communications, specifically the creation and character of networks that create viral phenomena (posts, images, videos, or links that are disseminated quickly and broadly via Internet-based communication and social networking services). An objective of the study was to measure the relationship between online size and influence, as measured by the act of passing along information. The research study focused on behavior on the Twitter social network, an online communication and social networking site that allows an author (site host) to post online or send via short message service (SMS, or “text”), “tweets” or short messages of 140 characters or less that are then read, and possibly reposted (“retweeted”) by network of people who subscribe to that author’s site (“followers”).

Internet TV

The networking capability allows messages to be quickly transmitted throughout branching chain of individual Twitter networks. Predictive and data analysis algorithms measured and relied on follower attributes, such as the follower’s record of activity, and sampled 22 million link-containing messages or tweets over a 300-hour period during September 2009. The data gathered indicated that the character of the audience, rather than the size of an audience, is more closely correlated to the creation of online viral phenomena.