Panasonic Corporation (Osaka, Japan) reports the development of two new 18650-type (18 mm in diameter, 65 mm in height) high-capacity lithium-ion battery cells[1] for use in laptop computers and environmentally-friendly energy technologies. The company boosted the capacity of 18650-type battery cells, which are widely used in laptops, by improving electrode materials. The newly-developed high-capacity 3.4 Ah and 4.0 Ah lithium-ion battery cells have an improved nickel based positive electrode[2], and the 4.0 Ah cell uses a silicon based alloy for the negative electrode instead of carbon[3].
The two battery cells can not only extend operating time of laptop computers but also power electric vehicles when assembled in a module[4]. Panasonic is currently testing a battery module that is constructed from many pieces of 18650-type battery cells. When used for the module, the new battery cells can also serve as a high-energy storage system for clean energy technologies including household photovoltaic systems and fuel cells.
Lithium-ion battery cells have become indispensable as a power source for cordless equipment, such as laptops, that supports a ubiquitous society. As cordless devices become more sophisticated and powerful, they require more robust battery cells.
At the same time, rising environmental concerns call for widespread practical use of renewable energy and electric vehicles to reduce CO2 emissions. To realize, high-capacity storage systems are essential. Because lithium-ion based storage systems are more compact and lighter than conventional storage systems using other types of rechargeable battery cells, high hopes are placed on the practical application of lithium-ion storage systems. The increasing range of applications for storage systems also demands higher levels of capacity, output, reliability and safety, along with high cost performance.
Panasonic has responded to these challenges with the new battery cells, employing its unique high capacity nickel based positive electrode technology as well as its material and processing technology which prevents deformation of the alloy-based negative electrode when subjected to repeated charge and discharge.
Development of the nickel based positive electrode enabled Panasonic to produce high-capacity, lightweight and highly durable lithium-ion battery cells. By improving the positive electrode, it has achieved the 3.4 Ah cell which offers 20 percent greater capacity than the current 2.9 Ah model. The 3.4 Ah cell will be mass produced in fiscal 2012 ending in March 2012. The 4.0 Ah cell, which has 30 percent greater capacity compared to the 2.9 Ah cell, uses a next generation electrode material, a silicon based alloy for the negative electrode, substituting carbon. The 4.0 Ah cell will be mass produced in fiscal 2013 ending in March 2013. These high-capacity battery cells can make high-energy battery modules.
On the new battery cells, Panasonic holds 337 patents in Japan and 136 in other countries including pending applications.
Comparison of Newly Developed Products and Previous Panasonic Products
3.4 Ah Cell (Newly developed) | 4.0 Ah Cell (Newly developed) | 2.9 Ah Cell (Current product) | |
Positive electrode | Nickel base High-density | Nickel base High-density | Nickel base |
Negative electrode | Carbon | Silicon base | Carbon |
Capacity | 3.4 Ah | 4.0 Ah | 2.9 Ah |
Average discharge voltage | 3.6 V | 3.4 V | 3.6 V |
Mass | Approx. 46 g | Approx. 54 g | Approx. 44 g |
Energy | 12.2 Wh | 13.6 Wh | 10.4 Wh |
Volumetric energy density | 730 Wh/L | 800 Wh/L | 620 Wh/L |
Recharging voltage | 4.2 V | 4.2 V | 4.2 V |
The iRAP report Large-Format Rechargeable Lithium-Ion Batteries For Electric Energy Storage In Transport - Types, Applications, New Developments, Industry Structure And Global Markets, estimates the 2009 market for lithium batteries for transportation applications to be about $80 million. In 2009, iRAP estimates the market to be flat or going down slightly, to $77 million. In spite of the recession, iRAP estimates the market to reach $332 million in 2014, for an average annual growth rate (AAGR) of 33.9%. Midway through the projection period, it is estimated that Li-ion batteries for HEVs, PHEVs and EVs will be in wider use, thereby providing a large growth rate.
Customized batteries for off-road vehicles and industrial vehicles such as electric fork lifts, golf carts and motorized wheel chairs, will have highest market share, reaching 51.9% of the market in 2009; by 2014, this share will decrease to 15%. In 2014, large-format lithium batteries for HEVs, PHEVs and EVs will have a 26.6% share of the global market, at $88 million.
Explanation of Terminology
[1] Lithium-ion battery
Non-aqueous electrolyte rechargeable battery that commonly uses lithium metal oxide as the positive electrode and carbon as the negative electrode.
[2] Nickel based positive electrode
Panasonic's proprietary positive electrode material based on LiNiO2, allowing for high capacity and durability.
[3] Alloy-based negative electrode
Next-generation negative electrode material in place of carbon. Current R&Ds mainly focus on silicon based material and tin based material.
[4] Battery modules
Power source for the environmental energy field, consisting of multiple 18650-type lithium-ion battery cells connected in series and parallel. Announced in October 2009 by Panasonic.
Panasonic Corporation is a worldwide leader in the development and manufacture of electronic products for a wide range of consumer, business, and industrial needs. Based in Osaka, Japan, the company recorded consolidated net sales of 7.77 trillion yen (US$78.4 billion) for the year ended March 31, 2009. The company's shares are listed on the Tokyo, Osaka, Nagoya and New York (NYSE: PC) stock exchanges. For more information on the company and the Panasonic brand, visit the company's website at http://panasonic.net.
