Li-polymer versions match ultrathin mobile phones

	The model i910 1,200mAh 3.7V Li-ion battery from Shenzhen Silvercell is designed for the Samsung i910 mobile phone.

Makers are stepping up product development efforts to enhance battery efficiency and safety.

Compact, high-efficiency Li-polymer types will gain more traction in China’s mobile phone battery industry as suppliers reflect trends in the handset sector. In addition to being lighter than Li-ion, the former is safer to use and can achieve a thinness of 0.55mm, making it suitable for ultraslim devices. Its market penetration this year is expected to grow another 5 percent.

Some companies predict that as prices narrow the gap with Li-ion rivals, the line will start breaching the mainstream in coming years. Besides increasing efficiency and developing streamlined models, they are directing R&D efforts toward improving product safety. More are securing international approval and complying with such requirements as the UN38.3 and MSDS despite the potential impact on overall costs.

Battery suppliers in China are piggybacking on the bullish mobile phone industry. Overseas sales have been steady in the past six months. Although demand from traditional cellular phones dipped slightly, orders from international vendors Apple, RIM, Nokia, HTC and Samsung for their smartphone batteries boosted shipments.

Data from the ITU place worldwide registered handset users at 4.6 billion as of end-2009, with 500 million new ones annually. At about 70 percent penetration rate, two out of three people own a mobile phone. Although global shipments dropped in 2009, and will likely dip again this year, exports will nevertheless exceed 1.1 billion units.

Phone makers will continue to release new models each year to meet growing demand. Even as orders slacken in some developed economies together with the slowing replacement market, inquiries in countries such as India and Africa will drive production.

Meanwhile, the influx of cell phones supporting the Android platform and Windows 7 will encourage users to purchase new versions, which will then boost battery sales. Most subscribers replace batteries after two years or just acquire another handset instead.

The typical capacity of mobile phone batteries ranges from 600 to 1,200mAh. The output voltage is 3.6 to 3.8V, while charging requires 4 to 4.2V.

Prices in general are between $1.50 and $3.20, depending on the materials and components used. With the same capacity, Li-polymer models are 30 percent more expensive than Li-ion. If both have the same size, the former will have extra 150 to 200mAh capacity than Li-ion.

Given the same capacity, NiMH versions are quoted 20 percent less but will be 30 percent heavier than Li-ion.

Besides the inputs utilized, testing fees can influence prices. UN38.3 basic evaluation, for one, requires $1,300, plus $75 for a 1.2m drop test. The other checks cover high altitude simulation, high and low temperature cycle, vibration and impact, and overcharging and discharging.

The preprocessing of one batch comprising 20 to 30 units costs $300. The evaluation lasts for four weeks, excluding festivals and public holidays. Urgent tests require $1,800 to $2,200. If two samples with different labels or housings can be regarded as one model based on UN38.3 definitions, one will be charged normal testing fees and the other sample will incur only $15 to $20 for the certificate.Meanwhile, the outlay for MSDS evaluation for one model is $400 to $500.

Makers of mobile phone batteries in Hong Kong are beefing up R&D capability to differentiate products and match latest cell phone trends. Most development work revolves around reducing the self-discharge rate, prolonging life span, improving PCB design and ensuring compatibility with new handsets and chargers.

Specifically, enhancements highlight form and capacity. Companies targeting the replacement market are increasing storage capacity and enhancing safety through overvoltage and short-circuit protection.

Dominating shipments from Hong Kong is the Li-ion type. The rising adoption of Li-polymer solutions is prompting some to introduce more compact and lightweight models based on the former technology. Cells are obtained locally or imported from Japan, South Korea or other countries, depending on customers’ requirements.

There are at least 20 suppliers of batteries in Hong Kong, mostly focusing on OEM services. Tier 1 operations include battery specialists that manufacture Li-ion, NiMH and other chemistries for mobile phones, notebook computers and other handheld gadgets.

Providers of mobile phone accessories comprise the second supplier group. Targeting the aftermarket, their batteries are tailor-made for popular handsets from Apple, BlackBerry, Samsung, LG, Sony Ericsson and other leading international players. Several companies, encouraged by the popularity of the iPhone, are releasing batteries specially designed for Apple’s products.

Mobile phone battery manufacturers in Taiwan are highlighting safety improvement in R&D initiatives. Toward this end, Industrial Technology Research Institute has developed self-terminated oligomers with hyperbranched architecture. The STOBA is aimed to prevent explosions and fires caused by the improper heating of the battery, excessive charging and short circuits. It is a nanograde high-molecular input added to the lithium battery to form a protective film.

Makers purchase UL-listed and RoHS-compliant cells for production. They implement strict in-house QC as well.

Besides enhancing safety, suppliers are looking at developing batteries that can be embedded into mobile phones, which is predicted to be the next major trend. This is because a declining number of users buy extra batteries for handsets. External battery packs, however, will continue to be offered, especially for emergency use.

In terms of chemistry, Li-ion and Li-polymer are mainstream. Power-hungry smartphones adopt the latter because of its high plasticity, capacity and security, and ultralight and thin form factor. A sustained uptake in the smartphone sector will buoy up sales of Li-polymer batteries for years to come.

Following Japan, South Korea and mainland China, Taiwan is a main hub for batteries for mobile phones and netbooks and laptops, the two major applications for the line. The island has more than 100 handset battery suppliers.

the majority of which emphasize overseas OEM and ODM projects. Most conduct production in the mainland to streamline costs.

Large enterprises can churn out millions of units a month, while midsize operations average hundred thousands. Highcell Tech Co. Ltd, for example, has the capacity for 800,000 units monthly.

Asia is the main export destination, followed by Europe and North America. The customer base includes OEM partners and distributors or retailers for the aftermarket.

Taiwan has an established supply chain for the line, covering materials and packs, that enables enterprises to achieve economies of scale. To increase efficiency, manufacturers are automating processes to shorten delivery times and at the same time maintain flexible production to meet both large- and small-volume orders.

Players nonetheless face tough competition from mainland rivals, especially those that can make battery cells and therefore offer lower prices. There are currently fewer than 20 cell providers in Taiwan, which means suppliers need to source the input from Japan, South Korea and the mainland. Only a few companies, including E-One Moli Energy Corp., have in-house capability for cell manufacture. As this accounts for more than 50 percent of total costs, the situation hinders Taiwan enterprises from controlling the outlay. Rising worker salaries are compounding the problem.