The rapid development of automotive lithium-ion batteries has greatly increased the presence of independent manufacturers (Part 1)

Since 2012, electric vehicles have been launched in large numbers, and the automotive lithium-ion rechargeable battery market has expanded rapidly. Orders from not only joint ventures with automakers but also independent battery manufacturers have increased. Even so, the competition for the development of automotive lithium-ion rechargeable batteries has just begun. Automotive battery manufacturers are actively working on the development of next-generation batteries. This article will introduce the latest development of next-generation materials, etc., which was interviewed at "AABC 2012" held in February 2012.

"The proportion of electric vehicles in new car sales will be increased to 2-5% in 2015 and to 10-25% in 2020" (Ford Motor Company, USA).

Not only Toyota, Nissan and Honda in Japan, but all major automakers around the world have begun to fully launch electric vehicles such as electric vehicles (EV), plug-in hybrid vehicles (PHEV) and hybrid electric vehicles (HEV) into the market.

At the same time, the market for lithium-ion rechargeable batteries for vehicles also began to take shape. It was lithium-ion rechargeable batteries for EVs that led the market in 2011. This was due to the successive launch of EVs equipped with batteries, including Nissan's "LEAF" (Chinese name: 葉风), Mitsubishi Motors' "i-MiEV" and "MINICAB MiEV", and France's Renault's "Fluence ZE" and "Kangoo ZE".

Automotive Energy Supply (AESC), which supplies lithium-ion rechargeable batteries to Nissan and Renault, said, "We have produced batteries for 45,000 EVs and 6,000 HEVs." Note 1.

Note 1) AESC currently has a production system for batteries required to produce 90,000 EVs and 10,000 HEVs per year. In terms of capacity, this is 2.2GWh per year; in terms of quantity, this is 1.82 million units per year. Currently, the company mainly supplies EVs to Nissan's "LEAF" and Renault's "Kangoo ZE" and "Fluence ZE", and HEVs to Nissan's "Fuga Hybrid".

Menahem Anderman of Advanced Automotive Batteries in the U.S. predicts that the market size of lithium-ion rechargeable battery packs for EVs will be approximately US$800 million in 2011, will exceed US$1 billion in 2012, and will reach US$2.5 billion in 2015 (Figure 1 Note 2).

Figure 1: The expanding market for lithium-ion rechargeable battery packs for vehicles
Lithium-ion rechargeable battery packs are expected to replace previous nickel-metal hydride rechargeable battery packs and continue to expand in market size. The figure was produced by this magazine based on the forecast of Menahem Anderman, the organizer of "AABC".

Note 2) At AABC 2012, Anderman announced market forecasts in his speech titled “Advanced Vehicle and Advanced Automotive Battery Market Trends.”

In addition, various automakers are also planning to launch PHEV and HEV between 2012 and 2013. In terms of PHEV, following the "Prius PHV" that Toyota began selling in January 2012, Honda plans to launch a PHEV version of the new "Accord" between the fall of 2012 and the beginning of 2013, Ford plans to launch the "C-MAX Energi" and "Fusion Energi", and Volvo Cars of Sweden plans to launch the "V60 plug-in hybrid vehicle".

As for HEV, German manufacturers are gradually launching products. In 2012, BMW plans to launch the "ActiveHybrid 5" and "ActiveHybrid 3", Daimler plans to launch the "E400 HYBRID" and "E300 BlueTEC HYBRID", and Volkswagen plans to launch the "Jetta Hybrid". In addition, Ford also plans to launch the "C-MAX Hybrid" and "Fusion Hybrid" in 2012.

Battery manufacturers have clear supply customers

As electric vehicles are fully launched on the market, the lineup of battery manufacturers used by various automakers has become clearer (Figure 2). Previously, in the field of automotive lithium-ion rechargeable batteries, in addition to independent manufacturers such as South Korea's LG Chem, there are automotive battery companies that have been established in joint ventures with automakers, such as AESC, Lithium Energy Japan, Primearth EV Energy (PEVE) and Blue Energy.

Figure 2: The main supply and demand relationship of lithium-ion rechargeable batteries for vehicles
The relationship between the main models equipped or scheduled to be equipped with lithium-ion rechargeable battery packs and battery manufacturers.

Recently, Sanyo Electric (now Panasonic), Toshiba and Hitachi Vehicle Energy, which independently developed automotive lithium-ion rechargeable batteries, have been confirmed to supply products to many automobile manufacturers.

For example, Panasonic announced in March 2012 that it would supply lithium-ion rechargeable batteries for Ford's Fusion Hybrid and Fusion Energi. The product was developed by Sanyo Electric, and Panasonic appears to be supplying 5Ah units for the Fusion Hybrid and 20.5Ah units for the Fusion Energi. The 20.5Ah unit is the same unit that is used in the Toyota Prius PHV.

The 5Ah unit has already been supplied to Audi's "Q5 Hybrid" and Volkswagen's Jetta Hybrid has also been decided to adopt it. Toyota has also announced that it will adopt it in a number of HEVs. In addition, Panasonic has also scheduled to supply the cylindrical unit "18650" for Tesla Motors' EV "Model S" and "Model X", as well as the EV "RAV4 ​​EV" jointly developed by Tesla and Toyota.

Toshiba and Hitachi are also expanding their customer base

In addition, among Japanese battery manufacturers, Toshiba has also made rapid progress in EV. Toshiba's automotive lithium-ion rechargeable battery negative electrode material uses lithium titanate (LTO), which has the characteristics of high safety, long life, and excellent low-temperature characteristics. However, the disadvantage is that the average voltage of the unit is only about 2.5V, which is more than 1V lower than the previous lithium-ion rechargeable battery.

Therefore, EVs equipped with 200-400V high-voltage battery packs require a large number of battery cells connected in series, which the battery industry believes is "difficult to adopt." However, in fact, in addition to being used in Mitsubishi Motors' i-MiEV and MINICAB MiEV models, Honda has also decided to adopt the "Fit EV."

According to a technician from an automobile manufacturer, the reason for adopting this technology is that the battery's state of charge (SOC) rarely deteriorates even when used within a wide range of changes, and its low-temperature characteristics are high. "The high limit value of the battery is also suitable for EV use."

In addition, among independent Japanese manufacturers, there are rumors that Hitachi Vehicle Energy is supplying products for Nissan's new generation HEV in addition to General Motors' (GM) HEV "LaCrosse" and "Regal". Nissan established a joint venture with NEC Group to promote laminated battery cells, but did not cooperate with Hitachi Group. However, it is estimated that considering the basic strategy of purchasing batteries from more than two companies, Nissan decided to adopt Hitachi Vehicle Energy's square cells.

In addition, among American manufacturers, the lithium-ion rechargeable batteries of A123 Systems of the United States are scheduled to be used in BMW's ActiveHybrid 5 and ActiveHybrid 3, Fisker Automotive's PHEV "Karma" and General Motors' new EV "Spark EV" scheduled to be launched in 2013. The characteristic of A123 Systems' lithium-ion rechargeable batteries is that the positive electrode material is lithium iron phosphate (LiFePO4, LFP). It is planned to supply cylindrical cells to BMW and laminated cells to Fisker and General Motors.

Battery cells account for less than half of the cost of a battery pack

The Advanced Automotive Battery Conference 2012 (AABC) was held in Orlando, Florida, USA, from February 6 to 10, 2012. At the conference, automobile manufacturers and battery manufacturers introduced the details of the lithium-ion rechargeable batteries that are equipped or scheduled to be equipped in new cars.

BMW and Fisker, which use batteries from A123 Systems, also took the stage to introduce their battery packs. BMW gave a speech titled "THE LIION-BATTERY OF THE ACTIVE HYBRID 5," which is about the battery pack used in its HEV ActiveHybrid 5, which is scheduled to be launched in the spring of 2012.

ActiveHybrid 5 uses 96 cylindrical cells with a capacity of 4Ah. There are 8 modules in total, with 12 cells in one module. The capacity is 1.35kWh, and the voltage range is 200-385V. The volume is 40L and the weight is 46kg. In order to suppress the degradation of the cells, BMW not only controls the SOC range of the battery, but also uses water cooling. Therefore, only 0.6kWh of the capacity is actually used.

BMW also mentioned the battery pack cost of the ActiveHybrid 5 in this presentation. The proportion of battery cells in the battery pack cost, excluding manufacturing processes such as assembly, has now dropped to less than 50%. The company believes that in order to reduce costs in the future, "it is necessary to reduce the cost of not only cells but also peripheral components" (Peter Lamp, BMW's cell technology manager) (Figure 3).

Figure 3: Unit cost drops to less than half of total battery pack cost
BMW gave a presentation on the details of the battery pack cost for the ActiveHybrid 5. The unit cost ratio in the overall battery pack is less than 50%. The cost of the battery pack does not include manufacturing costs such as assembly processes. The figure was created by this magazine based on BMW's data.

Fisker, a venture company developing PHEVs, has adopted A123 Systems' laminated battery cells. Its first vehicle, the Karma, was delivered in late 2011. Fisker introduced the Karma's battery pack under the title "Energy Storage System Design for Performance Extended Range Electric Vehicles" (Figure 4).

Figure 4: Laminated cells from A123 Systems
Fisker uses laminated cells from A123 Systems on the Karma. (Photo: Fisker Automotive)

Karma is a series PHEV equipped with two drive motors and one generator. It uses 315 laminated units with a capacity of 20Ah. 21 units form a module, which is equipped in a 3-parallel × 5-series manner. The capacity is 20.1kWh and the voltage is 336V. It can travel 80km on a single charge. When the battery is low, it can travel about 483km using the 2.0L turbo tandem 4-cylinder engine to drive the generator.

German manufacturers actively promoting unit standardization

At this year's AABC 2012, it can be seen that the ideas of various companies in battery pack design have begun to differ greatly. Japanese manufacturers such as Toyota, Nissan and Honda tend to use air cooling for battery packs and try to simplify the structure to reduce costs, while European and American manufacturers tend to use water cooling and manage the charge state and temperature of the unit in a specific small range.

Furthermore, German manufacturers have shown the idea of ​​standardizing unit capacity and dimensions to achieve commonality. At AABC 2012, BMW said it intends to standardize units through the German Association of the Automotive Industry (VDA) and promote the commonality of modules used in HEV, PHEV and EV so that they can be used in a variety of models. Commonality will help further reduce costs.

However, Toyota and others still insist that the equipment space of different vehicles is different, and the most suitable product equipment should be selected from a variety of units, and it is difficult to achieve unit standardization.