## Hitachi Develops Lithium-ion Batteries for Plug-in Hybrid Electric Vehicles

##### 12 January 2010
 Positioning of the new Li-ion cells for PHEVs. Source: Hitachi. Click to enlarge.

Hitachi and Hitachi Vehicle Energy, Ltd., which develops and manufactures lithium-ion batteries for automotive applications such as hybrid electric vehicles, have developed new lithium-ion batteries for plug-in hybrid electric vehicles, a first for the Hitachi Group. Starting from the spring of 2010, the company will begin shipping samples to automobile manufacturers in Japan and overseas.

The newly developed cells have a capacity of 25 Ah, about 4-5 times the capacity of the Li-ion batteries for hybrids that Hitachi has been developing up to now. Energy density is 120 Wh/kg, power density is 2,400 W/kg. The cells incorporate a heat-resistant separator that prevents internal short-circuits and dramatically improves safety. The heat-resistant separator adopted in these new batteries was specially designed and developed for automotive applications, based on ceramic separator technologies.

To accommodate larger battery sizes, a variety of simulation technologies, including structural analysis and vibration analysis, were utilized to increase battery strength and enhance the collector structure. In collaboration with Hitachi Research Laboratory and the Mechanical Engineering Research Laboratory, Hitachi has achieved a battery structure with an even higher level of reliability than previous units.

In 2000, the Hitachi Group became the first in the world to begin volume production of safe, high-performance, long-lasting automotive lithium-ion batteries. Since then, it has brought a cumulative total of 900,000 cells to the market, mainly for commercial hybrid buses and trucks, as well as for railway cars and other applications. The lithium-ion batteries being released today will serve to further expand the range of applications, not only in automobiles, but also in the Social Innovation Business, which is a core area of business for the Hitachi Group; for example, in railways, construction and industrial equipment, power storage devices, and other industrial fields.

Hitachi Automotive Systems, Ltd. will market these automotive lithium-ion batteries. Hitachi will also display its PHEV lithium-ion batteries at the 1st International Rechargeable Battery Expo, which will be held at Tokyo Big Sight from 3-5 March 2010.

Hitachi’s development activities used some of the results of research contracted by the New Energy and Industrial Technology Development Organization (NEDO). Hitachi has been participating in a national project related to large-scale lithium-ion batteries being promoted by NEDO and the Japanese Ministry of Economy, Trade and Industry since 1992, and will continue its efforts to incorporate the results of such contracted research into practical applications as quickly as possible.

It's encouraging to see a EV battery manufacturer in their 10th year offering 4-5X larger, better batteries this spring.

These rugged batteries, with high power density and average energy density, would be well suited for heavy trucks, buses, locomotives and similar vehicles.

It's great to see each and every company advancing batteries. I assume the real value for this one is the high power density which is important for HEVs and their smaller battery packs compared to EVs.

The Panasonic announcements of batteries with energy density of about 267Wh/kg is much higher than the batteries they are announcing here, but I can't find any data on the Panasonic cells for power density. So I'm assuming the trade off is for more power here?

How economical are the batteries? Would a Tesla need ~1/8 as many of these batteries and management units? Could put the price under $100,000.. Before A123 Systems and Altairnano, Hitachi had the best power dense lithium ion battery. The number of charge/discharge cycles were off the chart too. Then they simply dissapeared. I hope this time they stick to it and start mass producing these batteries so that we have some healthy competition.$10000 for a Prius battery module from A123 Systems is simply obscene.

The energy density is a bit scary - 120 KwH / Kg.
So a 50 KwH battery would weigh 400 KG!
If we assume this gives 150 miles of driving (using 75% of the rated capacity), this yields a driving weight of 2Kg / mile (say 2.7 to be conservative).

You can see the problems for BEV makers - the PHev guys can get by with 40 miles = 108 KG of batteries, but a BEV with a 100 mile range needs 270 KG.

What you need to do is to size the battery for a PHEV so that 90 - 95% of your journeys (not miles) can be all electric, and don't sweat the other ones.

A modular battery (as many people have said already) would be very good - you start with say 20 mile range, use it for a month and then analyze the usage (on a built in car computer or laptop).

This could then predict the fuel savings if you went to 30 or 40 mile EV range.

The modular battery would allow people to have "just enough" battery capacity without fretting that they had underdone it.

Same story, but 2013? http://www.reuters.com/article/idUSTRE60B1KI20100112

I don't understand why they're trying to go for 250ish mile ranges yet. The batteries are too expensive and too heavy across the board at this point.

It seems like it would be much better to shoot for a "150ish" range for now...at the most. Once you're over 100 miles, it gets rid of range anxiety for any reasonable local driving and the car would be so much more affordable.

How often does the average person drive over 150 miles in a day? This would allow them to get their feet wet with some people who would be a better profile for working out the kinks. Will it be ready for everyone? Clearly not. But is a manufacturer ready to support "everyone" yet? Clearly no as well.

Within a two years, maybe three, they could move up to the 200-250 mile range.

I don't think it would impact early sales numbers and they couldn't handle huge volume sales the first year or two anyway.

By the "second generation" they could be offering the 200-250 mile version as an option and by that time the batteries available will be lighter, cheaper and more efficient.

Why try to make an EV the equivalent of a full ICE machine right out of the box when you don't have to do so????

Sorry, I clearly wandered over to full EV territory with that last post when this story was about HEVs. Oops.

Modular plug-in batteries may be a better approach for first generation PHEVs and BEVs.

Each first generation standardize module could give 5 to 10 miles e-range. Future generations could give 2x to 4x more e-range each module.

Owners could add more modules when they can afford it or whenever battery performance and price is more favourable.

Wonder why governments are not supporting the idea with R & D financial support..

Um folks... they arnt 4-5 times higher energy density nor power density they are in fact mostly just BIGGER and heavier with an increase in ah of 4-5 fold over the much smaller lighter batteries they were making before now.

Right, 4-5 times bigger. This will reduce packaging inefficiencies a little. Step in the right direction, no big difference inside except the safer separator. Still good to see a main line company make the jump from generic use little cylinder batteries to true automotive prismatic.

What I don't get is that we read about Li-ion component innovations left and right (better separators, better annodes, better cathodes, better electrolytes, better geometries) and yet the end result to date from the largest and best resourced vendors is still the kind of charge density, power density, and # of recharge cycles we've been seeing for 6 years. Ugh.

The comments to this entry are closed.