Heater for lithium ion battery of automobile and stationary

Effect of ambient temperature on lithium ion batteries

Internal resistance of lithium ion batteries increases on low temperature and so power reduces.
Therefore it is necessary to warm batteries on cold regions.

LLC heater as a lithium ion battery temperature control system for EV

We developed high efficiency LLC heater with 2-stage flow path by sandwiching a PTC with unique comb electrodes between two heat sinks.
By circulating the heated LLC around the lithium ion battery, it can be fully charged even at low temperature.

• small size and light weight
• Self-temperature control of PTC eliminates the need for an external control circuit and reduces cost.
• High-speed temperature rise by double-sided comb electrodes and two stage flow channel

Differentiation by double-sided comb-shaped electrode structure

As shown in Fig.1, conventional PTC heaters have a structure in which electrodes are provided on both surfaces of the element and power is supplied from there.
As a result, heat point is generated inside of PTC, and surface temperature of PTC does not rise because the current do not flow.
Also, the side of the heat sink where we want to take out the heat does not get hot, and the opposite side gets hot, making it difficult to achieve high output.
Our PTC, which has comb-shaped electrodes on both surfaces of the element, has a heat-dissipating surface and a heat-generating surface that are the same as shown in Fig. 2, heat can be obtained efficiently