A battery of questions about lithium ion

With no suitable replacement for lithium ion batteries on the horizon, slow progress on this notebook battery technology may have to do.
Written by Tom Krazit, Contributor
Eight hours of battery life--the stated industry goal for mainstream notebooks--feels like it has been eight years away for eight years.

PC components have grown more efficient, but then powerful graphics chips eat up the energy savings. Hard drives with moving parts are gradually handing over tasks to flash memory, but then faster Wi-Fi chips cause the battery meter to plunge.

After years of addressing the demand to lower power consumption in notebooks, it's time to point fingers at the supply: the lithium ion battery.

Manufacturers have been pushing lithium ion to its limits in recent years. The result of that push has included slightly longer battery charges--and safety disasters, such as the massive recall of Sony batteries in 2006.

"Some of the problems you see in the industry are (partly from) the need to over-engineer the system and having huge cost pressure," said Christina Lampe-Onnerud, founder and CEO of Boston Power, a battery developer.

Lithium ion technology was considered a fantastic solution when it was introduced commercially in the early 1990s. But there's no more room for improvement without pushing the envelope of cost and safety, Lampe-Onnerud said.

New materials
As a result, battery manufacturers have been experimenting with new materials, which could offer major breakthroughs--and lead to the unintended consequence of making life a little more difficult for notebook vendors.

For example, Panasonic, one of the three major battery vendors along with Sanyo and Sony, has developed a new battery cell that can hold more of a charge than the standard cell. (A standard lithium ion battery holds six cells.)

Panasonic doesn't discuss the materials being used to build that cell, but it is one of many companies investigating the use of metals other than lithium, such as nickel and manganese, on the cathode of the battery, said Andy Keaths, power sources enabling manager at Intel.

Some of the problems you see in the industry are (partly from) the need to overengineer the system and having huge cost pressure.
--Christina Lampe-Onnerud
CEO, Boston Power

Right now, Panasonic is using those new cells in batteries only for its own notebooks. But one day, it could license that technology to other manufacturers, which might also come up with their own new materials for both the cathode and anode of a battery. Intel is also looking at alternative metals and power sources over time, with investments in companies such as Zinc Matrix Power.

Those alternative metals present problems of their own, however, because they can require slightly different charging voltages and can add cost to the battery, said John Wozniak, who holds the title of distinguished technologist in Hewlett-Packard's notebook engineering group. It can also take awhile to introduce new, unproven materials.

"Right now, when I see road maps that say we're going to have this capacity at this time, I plan for something like six months after that," Wozniak said.

Working with what's there
Barry Huret, president of battery consulting firm Huret Associates, isn't quite so pessimistic about the future of lithium ion battery technology.

"They just have to get what they are using under the best control," he said.

In that vein, instead of focusing on extending battery life, Boston Power is working on designs that improve reliability, performance and safety of lithium ion technology. For example, the company wants to create a battery that doesn't lose its charge capacity over time, as opposed to current batteries that become more impotent as time passes.

This could be a big selling point for HP's enterprise customers, which currently buy three-year warranties on notebooks but are only entitled to one-year warranties on batteries, Wozniak said. If customers must live with small increases in battery life, perhaps they'll respond to other selling points when it comes to batteries.

"If I can't get all-day runtime, maybe I can do a fast charge at lunch," he said.

Still, any improvements will need to align with a renewed focus on battery safety, an issue that has haunted the industry since the series of battery-related laptop fires last year that led to the largest recall in the history of the consumer electronics industry.

The culprit for those problems was a defect in Sony's manufacturing technology that left small pieces of metal inside battery cells. When jostled, the metal pieces could work their way through the thin walls of a cell and let an electrical charge run rampant through the battery.

Think of a battery cell as a tiny can of soda. There's only so much room in that can--which typically measures 8mm in diameter and 65mm long--for an electrical charge, and the lithium ion battery industry has reached a point where it's getting exceedingly difficult to keep cramming an electrical charge into those cells and to ensure the cells fit safely into a battery pack, Lampe-Onnerud said.

"Any time when you are aiming to put energy into a confined space, you should understand how that should be deployed," she said.

Incidents with lithium ion batteries are extremely rare, Keaths noted, but they have a way of resonating with the public.

Sony profusely apologized for last year's problems, and it paid a hefty price for the massive recall.

Legacy of the recall
The legacy of last year's incidents have been a variety of new standards and regulations, Huret said.

For example, the Japan Electronics & Information Technology Industries Association and the Battery Association of Japan recently released new standards that call for a maximum charging voltage for the current generation of lithium ion batteries, and the Institute of Electrical and Electronic Engineers and the Department of Transportation are working on similar guidelines, Huret said.

Aside from last year's problems, battery cell manufacturers have been able to make some innovative changes to keep boosting the performance of their products. Still, it's only been good enough to improve performance by 7 percent or so each year.

That's hard to stomach for an industry that has grown up with Moore's Law. Making the cell walls thinner and thinner has been one of the primary ways to improve performance of lithium ion batteries. But it's hard to imagine those walls growing much thinner after Sony's experience last year.

Unless the PC industry decides to place its bets on another charging technology for future notebooks, battery life may be stuck in neutral as the industry focuses more on safety and reliability.

Eight-hour battery life does exist today, for some notebooks, but that requires extended batteries, expensive energy-saving chips, or both. Eight hours won't be a realistic vision for mainstream notebooks until later in the decade, noted Kamal Shah, manager of Intel's mobility-enabling initiative.

Emerging technologies like flash-memory drives and energy-saving displays will continue to help make a difference, he said. "A lot of things will come together by the end of the decade with an incremental improvement in battery technologies," Shah said.

Editorial standards