Magical Coil - A Necessary Condition for Wireless Charging

Whether using the principles of electromagnetic induction or electromagnetic resonance, coils are an important component of wireless charging technology, and the energy loss caused by coils has a significant impact on the efficiency of wireless charging.

So what are the materials for wireless charging coils?

Copper coil is a widely used material in wireless charging technology, mostly used for the receiving end of wireless charging. Copper is a metal material with extremely low electrical resistivity, second only to silver in conductivity, and has the advantages of low cost and good ductility. In addition, copper has a good heat dissipation effect, which can effectively disperse the heat generated during the charging process and avoid overheating.

Leeds wire is a commonly used coil material for wireless charging transmitters. This type of wire is made of multiple strands of thin copper wire twisted together to reduce skin effect (uneven distribution of alternating current in a conductor), thereby reducing resistance and improving energy transmission efficiency.

Although copper and other metal materials have excellent conductivity, they have been widely used in wireless charging coils. However, for flexible electronic devices that come into contact with the skin, rigid coils such as copper are difficult to transform into different shapes according to different application scenarios. In addition, wireless charging electronic devices require a battery to store electrical energy in addition to the coil, which not only increases the size of the device but also increases its weight. So, can we store electrical energy directly in the coil without the need for batteries?