Higher power density top R&D goal in LiFePO₄ batteries

- Aug 04, 2017-

Development work focuses on materials that improve LiFePO₄ battery performance further as makers prepare for the surge in demand.12V 100AH-2.jpg

Greater power density drives R&D for China's LiFePO₄ batteries to complement production expansion amid projections of 50 percent growth in demand and sales in the next one to two years. Major companies have initiated and are stepping up development efforts toward this end. One enhancement is from BYD, which has achieved up to 125.6Wh/kg by using high-performance materials and optimizing battery pack structure. The current volume is 110Wh/kg.

Other makers look forward to eventually benefiting from ongoing research undertaken by local academic institutions. One breakthrough is in anode and cathode inputs from the School of Materials Science and Engineering, Huazhong University of Science and Technology. This yielded a power density of as much as 280Wh/kg per unit. As the work is still at the experimental stage, the availability of the actual materials will be announced later.

In the meantime, domestic suppliers introduce improvements to raise product competitiveness. OptimumumNano are among those that have released water-resistant LiFePO₄ batteries. The first has a 12V model with a capacity of 100Ah for caravan backup power supplies, UPS and emergency power supplies, and the latter with 10Ah. Both units have an IP65 rating.

LiFePO₄ batteries form the bulk of China's production of power batteries, and NCM and NCA variants the remainder. Output totaled 15GWh in 2015, according to the CCID Group. It has been rising since, with suppliers such as Shenzhen Hailei New Energy Co. Ltd ramping up volume with demand. The maker implemented a 100 percent increase in 2016 and is expected to maintain momentum this year.

In terms of manufacturing capacity, the country's level will soar to 59GWh by end-2017. This will rise further in coming years as more makers enter the line, attracted by the boom locally and abroad.

There are more than 100 LiFePO₄ battery suppliers in China and over 70 percent are domestic enterprises and the rest with investment from foreign makers. Half of the makers gather in Guangdong province and the rest in Zhejiang and Jiangsu provinces, and Shanghai and Tianjin.

The major homegrown suppliers include BYD, Optimumnano, Hefei Guoxuan and Contemporary Amperex, with the first also engaged in the production of electric vehicles or EVs.

NCM, NCA batterieson agenda

NCM and NCA batteries have attracted great attention in the global power battery market in recent years because of their high power output and enhanced performance in low temperatures.

In China, many makers of LiFePO₄ types also offer NCM and NCA variants. They are taking advantage of opportunities in the passenger vehicle industry, which will maintain an annual shipment growth surpassing 50 percent from 2016 to 2018. More than 70 percent of the country's power batteries delivered for this application are the latter kinds, according to the CCID Group. As a result, the shipped volume of these batteries will exceed that of LiFePO₄.

Local companies anticipate extra impetus for the NCM and NCA segments from Tesla's recent release of 2170 NCA battery cells replacing the current 18650 units for EVs. The new product can lower the required quantity of cells by one-third while providing the same power density.

The LiFePO₄ category, in turn, will continue to be widely adopted in commercial vehicles, accounting for over 70 percent of China's aggregate power battery shipments for this sector. This is because the chemistry is safer than their NCM and NCA rivals and has added performance benefits of stable discharge current, long operating life, environment friendliness and low cost. With such attributes, LiFePO₄ batteries are regarded as the best choice for EVs.