Japanese electronic parts maker TDK on Monday said it had successfully developed a material for its solid-state batteries, making a breakthrough that it estimates could deliver significantly higher performance for wearable devices.

The Tokyo-based Apple supplier said the material for its small solid-state batteries had an estimated energy density of 1,000 Watt hours per liter, or Wh/l, which is approximately 100 times greater than the energy density of TDK’s conventional mass-produced solid-state battery.

Energy density refers to the amount of energy stored in a region of space.

Solid-state batteries are viewed as a potentially game-changing technology because they can store more energy than lithium-ion batteries and charge faster.

TDK said the innovation can be utilized in various devices that come into direct contact with the human body, including for wireless earphones, hearing aids and smartwatches.

The batteries are expected to be produced with an all-ceramic material, with oxide-based solid electrolyte and lithium alloy anodes.

TDK said its goal is to use its technology to replace existing coin cell batteries, a small stainless steel disc that provides power to portable devices, in compliance with European Union battery regulations.

Some of the main features of TDK’s technology include the use of oxide-based solid electrolytes, which the company says makes them “extremely safe.”

TDK says the smaller size of the battery and its higher capacitance, the capability of a device to store electric charge, means it can contribute to smaller devices and potentially provide a longer operating time.

— CNBC’s Ganesh Rao contributed to this report.