The B2B platform for full-electric and plug-in hybrid electric vehicles: Industry News

In our weekly scan of original Japanese media, this time we give you a short overview on Showa Aircraft Industry's prototype of an innovative wireless EV charging system, Hitachi Cable's surge-resistant enameled wires for EV motor windings, and an analysis of Japanese secondary lithium-ion battery manufacturers' market power.

Circular coiled sending unit

Showa Aircraft Industry presented at the TECHNO FRONTIER 2010, held last month in Tokyo, an improved version of their wireless charging system using a resonance mode of non-contact charging technology.

In contrast to other wireless charging models where sending and receiving units are laid out in straight lines, Showa has arranged the receiving unit in the car in circular coils, rendering the system more efficient. In a miniature model, the company demonstrated that the principle of resonance charging can still be applied despite the two units having different forms. The frequencies of the sending and receiving device are aligned and lie in a 200kHz range.  

Surge-resistant wires

At the EVEX 2010 last month in Tokyo, Hitachi Cable Ltd. presented an inverter-surge-resistant enameled wire for motor windings in EVs and HEVs increasing the resistance of the motor insulation coating.

Insulation systems for motors are essential because inverter outputs have an overlapping surge (high steep pulse) voltage. High voltage is observed between individual wires in windings when a surge occurs. Therefore, to solve this problem, an inverter-surge-resistant enameled wire is necessary.

Hitachi Cable has developed an inverter-surge-resistant enameled wire and used it in organic/inorganic nano-composite insulation material. These materials exhibit good voltage endurance and good general properties. The polyamide-imid enameled, small-sized rectangular wires can be used in hostile winding conditions or severe environments. The wires, between 1 mm and 10 μm thin, have a life time 1,000 times greater than that of conventional enameled wires when they are used at voltages approximately the same as that of a typical inverter surge voltage (at 1.1 kVp).  

Patent score and market force

Comparing the patent score of the patents they hold in the field of alloy-based negative electrode materials for secondary lithium-ion batteries, Sony ranks highest, Panasonic second, Mitsui Mining and Smelting comes third, with Sanyo and Canon following closely. Using an anode mix including a silicon- or tin-based material as an anode active material, these companies achieve up to 10 times higher capacity in the electrodes of their secondary batteries than others using graphite or coke as carbon base for the anodes.  

Sony, both ranking high in quality and production scale, holds 218 patents in the field and is judged to hold the strongest market position in the Japanese secondary lithium battery market.

The original articles are listed below in the order of appearance in the column.