Application Watch: Electric vehicles: Lithium, lead-acid batteries for hybrid, pure EVs

The range in China has LiFePO₄, ternary, and AGM, gel and semigel lead-acid types.

China manufacturers of power storage batteries are positioning for the broadening electric vehicle industry, emphasizing lithium and lead-acid types. They target to benefit from the application's projected market of $109.8 billion in 2019 from $73 billion in 2014, which according to BCC Research, translates to nearly 9 percent CAGR. Companies are preparing for the automotive sector's rapid shift from hybrids to pure EVs, which will increase the requirement for power sources further. Based on Infinity Research's estimate, the global EV battery segment will post 59 percent CAGR during the same period.

The local mainstream selection for hybrid and pure electric cars, buses and trucks consists of Li-ion units, which boast enhanced safety features and long life span. It includes mainly LiFePO₄ and ternary kinds, with the former dominating production because of performance advantages. LiFePO₄ batteries support operating temperatures of up to 60 C and do not explode or catch fire. Their peak electric heating value can reach 350 and 500 C. The units withstand a maximum of 3,000 cycles. The 130Wh/kg energy density, however, is comparably low.

To address the last issue, local companies such as Tianjin STL and BYD have developed LiMnPO₄ cathode materials to raise energy density by 10 to 15 percent or above 150Wh/kg. The latter, which is also a carmaker, will begin manufacture in coming months and will adopt the battery in its own EVs.

Suppliers of ternary kinds are therefore upbeat about the category as existing models can already reach 180Wh/kg. Shenzhen BAK Energy Co. Ltd is bolstering production of EV-use units, which currently account for about 20 percent of its Li-ion yield. The target share is between 30 and 40 percent.

Consistent with this trend and providing additional encouragement is the government's draft plan for green vehicle development in China, which was released by the Ministry of Science and Technology in February this year.

The program covers the target EV battery energy density levels, which should be 200Wh/kg by end-2015 and 300Wh/kg in 2020.

For low-speed EVs such as bicycles, scooters and motorcycles, lead-acid batteries constitute China's typical lineup and include mainly AGM and semigel units. The last has glass mat separators and is the less expensive alternative to gel kinds adopting micropore PVC-SiO₂. Semigel variants have the attributes of conventional AGM types but have better reliability features. They dominate supply at present.

To buoy the traditional category, some local makers continue to pursue the development and manufacture of gel kinds to meet higher-performance requirements. The batteries support -25 to 60 C operating temperature and 800 to 1,500 cycles, outstripping AGM counterparts' -15 to 40 C range and 600 cycles. They exhibit greater vibration and shock resistance as well.

Overall, battery companies sustain initiatives to improve product performance and strengthen market competitiveness. They believe all three power storage options will coexist in the long term as each has niche applications. LiFePO₄ batteries are expected to be the key choice in HEVs, while ternary kinds will have an increasing market share in EVs. Lead-acid chemistries will stay in the mainstream in low-speed EVs.

There are 84 suppliers of EV-use Li-ion batteries in China, more than 90 percent of which are locally owned. They congregate in Guangdong, Jiangsu, Shandong and Zhejiang provinces, and Tianjin city. Intense rivalry, however, will reduce this pool to 40 in the years ahead.

Even so, annual manufacturing capacity for Li-ion power batteries is projected to surge 179 percent, hitting 20.4 billion Wh by 2015's end from 7.3 billion Wh last year. Based on production value, the line will reach $26 billion from $1.7 billion, posting 31 percent CAGR.

Lead-acid batteries have about 300 makers in China, which churned out 220.7 million kVAh in 2014 or nearly 5 percent higher than the preceding year. The volume represents 40 percent of the total worldwide, making the country the largest hub for the chemistry. The provinces of Hebei, Hubei, Guangdong, Jiangsu and Zhejiang are the key production bases.

Li-ion batteries

Mostly used in electric cars, buses and trucks, and HEVs, the local selection includes models with 40 to 600Ah and 400 to 500V and 700 to 800V nominal capacity and voltage. As the chemistry is also increasingly adopted in low-speed EVs, there are also variants in 10 to 200Ah and 36 or 48V.

Optimumnano Energy Co. Ltd focuses on LiFePO₄ units. Its Li-ion battery modules for EVs boast 40 to 600Ah rated capacity and come in 76.8 to 576V versions.

As for Shenzhen BAK Energy, LiFePO₄ makes up about 80 percent of output, and ternary kinds the remainder.

Anode and cathode materials, electrolytes and separators are the key inputs in the production of Li-ion units. These come from domestic providers, while separators are also sourced from foreign companies such as Asahi, Celgard and Tonen.

With the rise in requirement, localization continues to accelerate. Upstream suppliers are, in fact, ramping up production. In 1Q15, China's output of cathode and anode materials for Li-ion batteries hit 16,950 and 12,200 tons, rising about 23 and 28 percent from the same period in the previous year. That of electrolytes touched 10,500 tons or nearly 24 percent uptick. Separators climbed by almost 41 percent and reached 98.5 million square meters.

In 2014, domestic yield totaled 75,900 and 52,000 tons respectively of cathode and anode inputs, 42,400 tons of electrolytes and 420 million square meters of separators, improving 26, 33, 26 and 57 percent YoY.

LiFePO₄ and ternary materials registered a substantial increase in volume, especially the former with more than 100 percent growth.

From these developments, prices are expected to remain in a downward trend in coming years.

Lead-acid batteries

Typical units have 10 to 200Ah rated capacity, 6, 8, 12 or 16V nominal voltage and 600-cycle life span. These target electric golf carts, cars used in sightseeing tours, forklifts and wheelchairs, in addition to electric bikes, scooters and motorcycles.

The main materials used in the production of lead-acid batteries are lead, vitriol, separators and plastic.

The relatively stable cost of lead will keep quotes at current levels until year-end.

See a comparison table of power storage battery suppliers on GlobalSources.com