EV Industry Experts in Taiwan Talk About Progress Made So Far

Integrating industrial-academic

Experts with ambition and years of experience, know-how in energy storage as well as vehicles in Taiwan believe they have the solution to a thorny problem—to develop a truly practical battery technology that suits various electric vehicles (EVs), including e-bicycles, e-scooters, multi-wheeled electric cars and buses etc., tapping technology that has been built up over the last 30 to 50 years.

Made up of doctorates with multi-disciplinary expertise, professors, management experts etc., these professionals have been helping Pihsiang Machinery Manufacturing Co., Ltd. (PMMC) and affiliated Pihsiang Energy Technology Co., Ltd. (PHET), trying to prove that at least one of Taiwan's lithium-ion battery makers can equal or even better major global players in Japan and South Korea, aiming to develop in-house innovative battery systems that will be optimal for transportation equipment of various kinds.

Some progress has been made so far, with the two key men responsible being Dr. Donald Wu., CEO of major LiFePO4 battery maker and chairman of PMMC; and Peijen Wang, professor of National Tsing Hua University and senior advisor at PHET.

In a recent interview, Dr. Wu said: "The LiFePO4 battery is the best energy storer developed in the past 30 to 50 years, and PMMC and PHET are integrating mutual resources to help popularize, raise the practicality electric vehicles as e-bicycles, e-scooters, and e-cars." PMMC, in fact, is already the world's largest maker of hospital-use electric scooters. And after acquiring a lithium-ion battery plant, PMMC has been renamed “PHET,” which has been promoting assembled electric-vehicles using its own LiFePO4 batteries.

World's Only

The world's only volume maker of C-LiFePO4 batteries with automated production, PHET has been exclusively-licensed by Phostech Lithium Inc. to make, market, and distribute patented C-coated LiFePO4 cathode films and batteries for electric bikes, electric scooters, hospital wheelchairs and scooters, as well as being authorized to supply such batteries to meet any market demand.

We are proud of successfully becoming a major supplier in the global EV industry, able to build, assemble batteries and vehicles independently, says Wu.

"The main feature of the system is to protect each cell in the system individually by a serially connected quick-blown fuse with or without a light-emitting diode (LED) indicator," the inventor said. "The protected cells are then connected in serial or parallel configuration and encapsulated by a prismatic plastic box together with a voltage-balancing circuit. The proposed system can further enhance the inherent safety of the C-LiFePO4 chemistry to a road-worthy level. In addition to the robustness in safety of the DOSBAS battery system, the total cost of a system is significantly reduced by replacing the isolated malfunction cells in the battery system during maintenance services."

In comparison with other battery system packed with large-format cells, such as 18650 or 26650 cells, or even lithium-polymer cells, can be employed in the system for reducing

Costs and enhancing reliability. "The BOSBAS safe battery system is devised as a trade-off of performance, safety, reliability and costs in the battery systems for EV or hybrid electric vehicle (HEV) applications," Wu claims.

High Voltage

Although here are many "high voltage" cathode materials being tested continuously in the past years, LiCoO2, LiNiO2, LiMn2O4 are the most commonly reported potential chemistries, the CEO and chairman explained. However, PHET and some researchers believe the C-LiFePO4 is one of the most promising technologies because its charge and discharge properties at high operating temperature could circumvent the problems of thermal runaway. Nonetheless, when battery cells are packed into battery systems, performance safety and abuse test must be conducted on the systems to characterize the responses of integrated battery system to expected and worse-case accidents and abuse situations. Under no circumstance, the battery systems should burst into flames or combustible fumes. Hence, the safety protection devices msuch be installed in the battery system if higher safety standard is adopted for battery system in HEV or EV applications.

"In the development process of EVs, the design of battery systems has long been the most challenging issue due to the high energy density and high power density requirements," Wu said. "Up to date, the problem has been alleviated in HEVs because the employment of internal combustion engine replenishes the energy deficiency of batteries avliable in today's market. However, the advent of lithium-ion chemistry may circumvent the difficulties in design of battery systems for electric vehicles. The safety issues of lithium-ion chemistry still concern the public in the past few years due to reported accidents either in the lab or on the road. We believe our DOSBAS is one of the best solutions."

Advantages

The DOSBAS can isolate any over-heated cell(s) caused by internal short-circuiting via a fuse device, and, it certainly will help prevent the normal cells from the thermal runaway of the system. Such design, Wu stressed, could not only prolong the cycle life of the battery pack but also prevent injury to the occupants by blocking damaged cells caused by external impact accidents. Also because of its simplicity in structure, the DOSBAS battery system has been proven to be able to withstand vibration and weather conditions by putting the system without casing through 150 hours in a salt mist chamber. A DOSBAS battery pack could also safely pass the short-circuiting tests with no temperature increase and cell damage.

With the C-LiFePO4 batteries protected by the DOSBAS design, a fleet of 23 EVs produced by PMMC/PHET has been road-tested with an average mileage of about 10,000 kilometers in Asia and Europe from 2007 to early 2009, Wu said proudly.

"The development of lithium-ion batteries for EVs and HEVs has been rapidly advancing," Wu said, "however, safety should always the first priority when the power density and energy density increase at a high speed. The DOSBAS system provides not only a cost-effective solution for meeting the current regulations but also a feasible engineering design for mass production in the relevant applications."

Commercialization-ready EVs

After the interview, Wu demonstrated several commercialization-ready pure electric cars, including two-seat, 2+2 seat, and mini pickup models. He said that the product positioning is very clearly delineated so as to escape strong pressures from global automakers.

The use of aerospace-grade technology in key parts such as plastic/composite body parts (which have a temperature tolerance of -45 to 95 degree Celsius) and aluminum-alloy structures and parts keeps the overall weight of the models to very light. This helps extend the vehicle's cruise range from the original 100 kilometers using a standard battery to up to 220 kilometers with an optional expanded-capacity battery pack.

According to Wu, these EVs have two C-LiFePO4 battery-pack options provided by PHET, including the GE1200 (general-purpose) and the EP1500 (high-performance energy cell). Road tests carried out by PMMC indicate that with power supplied by the bigger EP1500 pack, the EV can travel up to 152 kilometers at a speed of up to 80 kilometers per hour.

Fast Charge

The charging time also varies with fast-charge and standard battery models. Basically, the shortest charging times (using 230V power) for the GE1200 and EP1500 are only 1.1 and 2.0 hours, respectively.

The EV uses an AC traction brushless motor of the highest sophistication along with a transmission developed in-house by PMMC. "We can be sure that the EVs are one of the world's best pure-electric urban commuter vehicles," Wu claimed, "and that all of its sub-systems and key parts are very mature, including the world-patented fault-tolerant battery pack, dual-mode charger, controller, AC traction motor, drive-train, converter, and contactor."