Tamiya Toys History: Blog

lithium-ion high-power battery knowledge

Sat, 22 Mar 2008 07:36:09 -0500

Most lithium-ion batteries for portable applications are cobalt-based. The system consists of a cobalt oxide positive electrode (cathode) and a graphite carbon in the negative electrode (anode). One of the main advantages of the cobalt- based battery is its high energy density. Long run- time makes this chemistry attractive for cell phones, laptops and cameras.

The widely used cobalt-based lithium-ion has drawbacks; it offers a relatively low discharge current. A high load would overheat the pack and its safety would be jeopardized. The safety circuit of the cobalt-based 346970- 001 battery is typically limited to a charge and discharge rate of about 1C. This means that a 2400mAh 18650 cell can only be charged and discharged with a maximum current of 2.4A. Another downside is the increase of the internal resistance that occurs with cycling and aging. After 2-3 years of use, the pack often becomes unserviceable due to a large voltage drop under load that is caused by high internal resistance. Figure 1 illustrates the crystalline structure of cobalt oxide.

The battery industry is making incremental capacity gains of 8-10% per year. This trend is expected to continue. This, however, is a far cry from Moore's Law that specifies a doubling of transistors on a chip every 18 to 24 months. Translating this increase to a presario r3000 battery would mean a doubling of capacity every two years. Instead of two years, lithium-ion has doubled its energy capacity in 10 years.
Today's lithium-ion comes in many "flavours" and the differences in the composition are mostly related to the cathode material. Table 1 below summarizes the most commonly used lithium-ion on the market today. For simplicity, we summarize the chemistries into four groupings, which are Cobalt, Manganese, NCM and Phosphate.

Definition of Energy Density and Power Density

Energy Density (Wh/kg) is a measure of how much energy a pavilion zv5000 battery can hold. The higher the energy density, the longer the runtime will be. Lithium- ion with cobalt cathodes offer the highest energy densities. Typical applications are cell phones, laptops and digital cameras.
Power Density (W/kg) indicates how much power a battery can deliver on demand. The focus is on power bursts, such as drilling through heavy steel, rather than runtime. Manganese and phosphate-based lithium- ion, as well as nickel-based chemistries, are among the best performers. nx9600 batteries with high power density are used for power tools, medical devices and transportation systems.

An analogy between energy and power densities can be made with a water bottle. The size of the bottle is the energy density, while the opening denotes the power density. A large bottle can carry a lot of water, while a large opening can pore it quickly. The large container with a wide mouth is the best combination.

Confusion with voltages

For the last 10 years or so, the nominal voltage of lithium-ion was known to be 3.60V/cell. This was a rather handy figure because it made up for three nickel-based pavilion zd8000 batteries (1.2V/cell) connected in series. Using the higher cell voltages for lithium- ion reflects in better watt/hours readings on paper and poses a marketing advantage, however, the equipment manufacturer will continue assuming the cell to be 3.60V.
The nominal voltage of a lithium-ion 319411-001 battery is calculated by taking a fully charged battery of about 4.20V, fully discharging it to about 3.00V at a rate of 0.5C while measuring the average voltage.

Because of the lower internal resistance, the average voltage of a spinel system will be higher than that of the cobalt-based equivalent. Pure spinel has the lowest internal resistance and the nominal cell voltage is 3.80V. The exception again is the phosphate-based lithium-ion. This system deviates the furthest from the conventional lithium-ion system

In 1996, scientists succeeded in using lithium manganese oxide as a cathode material. This substance forms a three-dimensional spinel structure that improves the ion flow between the electrodes. High ion flow lowers the internal resistance and increases loading capability. The resistance stays low with cycling, however, the battery does age and the overall service life is similar to that of cobalt. Spinel has an inherently high thermal stability and needs less safety circuitry than a cobalt system.Low internal cell resistance is the key to high rate capability. This characteristic benefits fast- charging and high-current discharging. A spinel- based lithium-ion f4809a in an 18650 cell can be discharged at 20-30A with marginal heat build-up. Short one-second load pulses of twice the specified current are permissible. Some heat build-up cannot be prevented and the cell temperature should not exceed 80�C.

The spinel battery also has weaknesses. One of the most significant drawbacks is the lower capacity compared to the cobalt-based system. Spinel provides roughly 1200mAh in an 18650 package, about half that of the cobalt equivalent. In spite of this, spinel still provides an energy density that is about 50% higher than that of a nickel- based equivalent.

Types of lithium- ion batteries
Lithium-ion has not yet reached full maturity and the technology is continually improving. The anode in today's cells is made up of a graphite mixture and the cathode is a combination of lithium and other choice ls. It should be noted that all materials in a zd7000 battery have a theoretical energy density. With lithium-ion, the anode is well optimized and little improvements can be gained in terms of design changes. The cathode, however, shows promise for further enhancements. nx9500 battery research is therefore focusing on the cathode material. Another part that has potential is the electrolyte. The electrolyte serves as a reaction medium between the anode and the cathode.

Tamiya Introduction

Tue, 11 Sep 2007 21:11:37 -0500

It all started in 1946, when Mr. Yoshio Tamiya, the founder, opened a saw mill and lumber business in Shizuoka. Tamiya ventured into modeling in 1948, with a scale wooden ship model kit. Since then, Tamiya has continued to grow, producing models known as "First in Quality Around the World".

1946 May: A sawmill/lumber company is founded in Oshika, Shizuoka-City, Japan and named Tamiya Shoji & Co.

1948 Apr: A wooden model department is organized within the lumber company.

1953 Jun: Sawmill is closed, and Tamiya becomes a specialized wooden model kit maker.

1955 May: Tamiya releases a wooden motorized tank, whick becomes immensely popular.

1956 Mar: A boom in wooden ship models allows Tamiya to be- come widely known.

1960 May: Tamiya begins producing plastic model kits, with 1/800 Scale Battleship Yamato.

1961 Dec: Tamiya releases the first 1/35 scale moto- rized tank, Panther.

1962 Dec: The Tamiya Plastic Kogyo Co. is founded as a plastic molding company with a capital of 4 mil- lion yen.

1963 Tamiya introduces the follo- wing categories: 1/21 Scale Deluxe Tank Series with M4 Sherman, 1/50 Scale Japa- nese Aircraft Series with Type 52 Zero Fighter, 1/72 Scale Aircraft with Type 32 Zero Fighter.

1965 Mar: Tamiya goes into slot-car production with the release of 1/24 scale Jaguar D type

1966 May: Tamiya ventures outside of Japan by ex- porting to countries abroad, such as the U.S.A., Australia, Europe and South East Asia. Dec: The 1/25 Scale Military Tank Series is introduced with the German Panther tank.

1967 Jan: The first issue of Tamiya News is published. Aug: The first issue of Tamiya Junior News is published. Oct: The 1/12 Big Scale Series is introduced with the Honda F-1 racer (RA273).

1968 Jan: Tamiya participates in the German Nurem- berg Toy Fair for the first time. Apr: The Tamiya Plastic Kogyo Co. builds a new factory. Capital increase to 10 million yen. Jul: The 1/35 Scale Military Miniature Series is intro- duced with a WW2 German Army Tank Crew. Dec: The 1/100 Scale Mini-Jet Series starts with the Mig-19.

1969 Aug: The Tamiya Plastic Kogyo Co. is renamed the Tamiya Plastic Model Co., and capital in- creased to 14 million yen. Dec: 1/18 Scale "Challenge" Series is intro- duced with the Porsche 910.

1970 Jan: Tamiya organizes their first photo album contest. Dec: 1/6 Big Scale Motorcy- cle Series is started with the Honda CB750.

1974 May: 27 European agents gather in Shizuoka for the first Tamiya agent meeting. Nov: Tamiya releases their first R/C model, M4 Sherman tank.

1976 Nov: Yoshio Tamiya is awarded The Fifth Order Of The Sacred Treasure, by the Japanese Go- vernment, for his commit- ment to the industry. Nov: Tamiya releases the 1/12 R/C Porsche 934 Turbo that triggers the R/C car boom.

1977 Apr: The 1/24 Scale Sports Car Series is started with the Porsche 935. Apr: The 1/20 Scale GP collection is started with the Tyrrell P34. Nov: A shipping facility is completed next to the production factory. Tamiya's first R/C Racing Circuit is completed.

1978 Jul: 1/350 Scale Ship Series is started with the German Battleship, Bismark. Oct: A new Tamiya Circuit is completed near the production factory. Tamiya Plastic Co. Ltd. is founded.

1979 Feb: Tamiya releases 1/100 Scale Space Shuttle Orbitor. Dec: Begins construction for headquarters office.

1980 Jan: Tamiya News becomes a monthly issue. Dec: Finishes the 6 story headquarters building.

1981 Mar: Celebration for completion of the new headquarters office. May: 72 Tamiya agents gather in Shizuoka for a meeting and celebration of the new headquarters. Jul: 1/12 Scale Motorcycle Series is introduced with the Yamaha YZR500.

1983 Jan: The production facilities are automated and expanded for better productivity. Mar: Tamiya Shoji & Co. completes a 3 story warehouse and paint storehouse.

1984 Feb: Tamiya releases the Sound Activated Temple with great success. Mar: Tamiya Shoji & Co. establishes Tamiya, Inc. with a capital of 50 million yen. Oct: Tamiya sponsors a televised R/C car racing program that stimulates the market. R/C off-road cars become big sellers.

1985 Mar: The first issue of Tamiya Model Magazine International is published. Nov: Tamiya Plastic Co. Ltd., completes its own injection molding factory.

1986 Mar: 1/32 Scale Mini 4WD Racing Series is started with the Hotshot Jr. Oct: The 1/24 Scale R/C Tamtech Series is intro- duced with the Porsche 962C.

1987 Oct: Begins the expension of the headquarters facilities. Tamiya News clebrates its 200th issue. Nov: More than 10 million 1/32 Scale Mini 4WDs sold.

1988 May: 1/14 Scale QD (Quick Drive) Series is introduced with the Thunder Shot QD. Jul-Aug: The first Mini 4WD Racing Japan Cup is held at 16 locations around Japan. Dec: Tamiya sponsors a private team "ACP" to compete in the 11th Paris-Dakar Rally.

1989 Jan: More than 23 millions Mini 4WDs sold. Apr: The 8 story east wing addition to the head- quarters building is completed. May: Tamiya America, Inc. is established in Cali- fornia, U.S.A. Jun: Tamiya Europe GmbH. is established in Neuss, West Germany. Dec:More than 44 million Mini 4WDs sold. Dec: Tamiya again sponsors a private team "ACP" to compete in the 12th Paris-Dakar Rally.

1990 Feb: Tamiya, Inc. completes its Abe factory. Apr: Tamiya, Inc. completes its second shipping facility, a 5,317m2 in Oshika, Shizuoka. Jul: Monetary Donation to Tank Museum Bovington England. New hall named "Tamiya Hall". Jul: Sales of Mini 4WD exceeds 50 million kits. Sep: 1/24 Scale Sports Car Series reaches 100 cars with the Honda NSX.

1991 Mar: Tamiya becomes a sponsor for Team Lotus' 1991 F-1 Grand Prix Season. Apr: 1/35 Military Miniature Series reaches 150 items with the creation of U.S.Navy PBR 31 Mk.II "Pibber". May: First solar powered item, Solar Car Assem- bly kit is released, starting the Solar Mechanics Series. Oct: Tamiya ties exclusive contract with McLaren International for replication of F-1 cars. Nov: 1/28 Mini F-1 Series is started with Lotus 102B. Nov: 1/10, 1/12 Radio Con-trol Car Series reaches 100 cars with the release of "Top Force".

1992 Jan: Tamiya Model Magazine International becomes bi-monthly. Feb: As the year before, Tamiya sponsors Team Lotus' F-1 season for 1992. May: R/C racers from 12 countries across Eu-rope gather for the Tamiya Euro Cup R/C Cham-pionships. Jun: The die-cast Lotus 102B is released as the first model in the 1/20 Collectors Club. Jun: Headquarters for Tamiya America is founded, a 6,800m2, two story complex in Aliso Viejo, Ca-lifornia. Sep: "Solar Eagle", the first solar battery powered R/C car is released. Sep: The All Japan R/C Championships is held, using only Tamiya cars. Qualification races are held around the country, and winners are invited to Shizuoka to determine the best R/C driver in the country.

1993 Jan: It is decided that Tamiya sponsorship of Team Lotus' F-1 season will continue through 1993. Jun: 1/32 Super Mini 4WD is kicked off with "Liberty Emperor". Jul: 1/14 Scale R/C Tractor Trucks Series is started with "King Hauler". Jul: The Dinosaur Diorama Series is started with the first set, "Chasmosaurus". Sep: "Yamaha Round the World" starts the R/C Yacht Series. Oct: The R/C Glow-Engine Car Series is strated with the TR-15T.

1994 Mar: 1/12 Scale Master's Coachwork Series is started with the Caterham Super Seven BDR. Jul: 1/32 Fully Cowled Mini 4WD Series is started with "Magnum Saber", which goes on sale at this year's Japan Cup. Sep: Tamiya Philippines is established.

1995 Mar: TamiyaCon, a U.S. national scale modeling contest sponsored by Tamiya America is inaugurated. May: Tamiya Philippines production facility is established on Cebu Island, Philippines. Aug: Radio Controlled gli-der, "Peak Spirit RU", is released and the R/C Aviation Series is started Dec: Total Sales of Mini 4WD exceeds 100 million units. Dec: The 1/12 Scale Collector's Club Special Series is started with the release of the die-cast Honda F-1 RA272.

1996 May: Kakegawa Circuit, a 320m race track for R/C cars is opened in Kakegawa City, Shizuoka. As well as being open for public use, it serves as a testing ground for development of new R/C cars. May: Winning modelers from American scale modeling contest "TamiyaCon", are invited to the Shizuoka Hobby Show to display their creations at a modeling club exhibition. Jul-Aug: Popularity of Fully Cowled Mini 4WD explodes. Over 300,000 people in 15 venues across Japan take part in Mini 4WD Japan Cup. Jul: "Spin Cobra" starts 1/32 Scale Real Mini 4WD Series. Nov: United States (TCS) and European R/C Championships (Euro Cup) are held, and winning drivers are invited to Japan to participate in the World R/C Championships. Dec: 1/43 Scale Collector's Club-Mini, which features metal die-cast models, is started with the Kure Nismo GTR.

1997 Apr: Tamiya establishes scholarship for students of San Carlos University, Philippines. Sep: Tamiya Philippines production facility receives ISO9002 certification. Oct: 1/10 Scale R/C Boy's 4WD Racer Series starts off with release of "Voltec Figther", which comes complete with R/C system and battery.

1998 Feb: The 1/32 Scale Aero-Mini 4WD Series is started with "Max Breaker". May: Additional production plant (8,000m2) is added to existing Tamiya Philippines facility, further improving production capability. May: 1/32 Scale Mighty Mini 4WD Series is started with "Dyna Hawk". Nov: Tamiya R/C World Championships adds the Asian R/C Championships to the Japanese, American and European events, expanding the challenge of R/C driving to an international level.

1999 Oct: Subaru Impreza WRC '99 marks the debut of the new QD (Quick Drive) Sports Series, which features pre-assembled 1/10 scale R/C cars for entry level users. Nov: For the first time, Australian drivers attend R/C World Championships, which this year is held concurrently with "Tamiya Fair in Shizuoka" hobby exhibition.

2000 May: Fully operational 1/16 R/C Tiger I, which sets a new standard of sophistication in R/C tanking world, is revealed at the Shizuoka Hobby Show. May: "Flash-Trigger", first car of the 3-D track racing, Dangun Racers Series, is also introduced at the same show. Sep: XB (Expert Built) Series, which features R/C built-up and ready to run versions of existing Tamiya chassis, is inaugurated with the 1/10 Scale Mitsubishi Pajero.