Lithium-ion second-generation batteries - a stable supply of electrical power in smart houses
The "supply of electrical power" is the focus of a great deal of concern. In the midst of this, the word "smart house" is very topical. This apparently refers to a house where electrical power produced from sunlight is stored in storage cells, and the house itself wisely considers how to supply that electrical power. Did you know this word? We'd be at ease living in a house like that, wouldn't we.
The "center" of a smart house is the household storage cell, and the batteries "lithium-ion second-generation batteries*" apparently are used for this.
I didn't know but NEC appears to have a long history in the development of lithium-ion second-generation batteries. What was the process up to the present day? And, what kind of batteries are lithium-ion second-generation batteries? In this installment, I will visit NEC's Smart Energy Laboratories and ask loads of questions!"
- *"Second-generation batteries" refers to batteries that can be charged for re-use time and time again. They are "rechargeable batteries" and "storage cells."
Put in charge of large manganese-based lithium-ion second-generation batteries in 2001, he is a specialist in lithium-ion second-generation batteries and has continued to contribute to their long life and practical application.
Joined NEC in 2001. A young researcher who has been vigorously involved solely in the R&D of large manganese-based lithium-ion second-generation batteries.
- MitaDr. Utsugi and Mr. Kawasaki. Thank you for your time today. First off, could you tell us in simple terms what a lithium-ion second-generation battery is?
- KawasakiThis refers to the batteries that are in use in cellphones and notebook computers that everyone uses today. You'd be all right in assuming that almost all of the batteries used in mobile devices such as these are lithium-ion second-generation batteries.
- MitaSo lithium-ion second-generation batteries are in our immediate surroundings.
- KawasakiYes, they are. Chargeable batteries in the past had a tendency to become rapidly depleted even after being recharged moments before, if the battery is one which was recharged a number of times. In almost all cases, this was due to the "memory effect" phenomenon. Lithium-ion second-generation batteries, however, do not have this memory effect, you know.
- MitaSo a feature of lithium-ion second-generation batteries is that their durability as batteries does not change. Many times they are recharged.
- KawasakiMoreover, they are compact, lightweight and powerful. This is why lots have come to be used in cellphones and other mobile devices. However, NEC's lithium-ion second-generation batteries are slightly different. …I'll hand that over to Dr. Utsugi, my senior, since he is more familiar with that than I am.
- UtsugiNEC's lithium-ion second-generation batteries are a little different in type from the batteries that everyone uses in cellphones, for example. To make this explanation a little easier, let's take a look at history a little. Everyone knows that cellphones and notebook computers spread at an explosive rate from around the middle of the 1990's. This resulted in an accompanying need for small and durable rechargeable batteries.
- MitaI see. So that was why lithium-ion second-generation batteries started to gain attention.
- UtsugiYes, exactly. Though all of the manufacturers simultaneously set out to develop lithium-ion second-generation batteries, NEC dared to opt for a different type from the other manufacturers. Lithium-ion second-generation batteries are divided into two types according to the mineral used in their cathode. One of these is the cobalt-based batteries that the other manufacturers started to develop. While the other type was the manganese-based battery that NEC undertook.