TDK Corporation has developed a new material for its CeraCharge, a next-generation rechargeable solid-state SMD battery that promises an energy density of up to 1,000 Wh/L, 100 times greater than the company’s current production solid-state battery solution.
CeraCharge solid-state battery cell.
The new battery technology targets compact and space-constrained applications that demand high-density energy storage, such as wearable devices, wireless earphones, and hearing aids. An oxide-based solid electrolyte makes the batteries safe for devices that come in contact with the human body.
With its performance improvements, TDK views the new solid-state battery technology as a potential replacement for coin cell batteries, which the EU currently restricts due to environmental concerns.
CeraCharge Solid-State Batteries
TDK’s CeraCharge is a conventional, high-volume production solid-state battery platform and the “industry’s first rechargeable solid-state SMD battery”. The battery achieves high energy densities using multilayer technologies similar to those in ceramic chip capacitors.
CeraCharge pulse power characteristics.
Unlike rechargeable lithium-ion batteries, which use highly flammable liquid electrolytes, solid-state batteries use an oxide-based solid electrolyte. Oxide-based solid electrolytes reduce many of the risks associated with rechargeable batteries, making them suitable for device applications that come in direct contact with the human body
The current iteration of CeraCharge operates at a nominal voltage of 1.5 V, with a typical capacity of 100 µAh and a pulse capability of 5 mA. It is available in a compact EIA 1812 surface-mountable case (4.4 mm x 3.0 mm x 1.1 mm) and supports a wide operating temperature range of -20°C to 80°C. The batteries are designed for reliability through over 1,000 recharging cycles.
CeraCharge, rechargeable solid-state SMD batteries
With a significantly higher energy density (100 times more than current production batteries), the new materials will make CeraCharge solid-state batteries both smaller and lighter, extending operating times. The lithium alloy anodes will also contribute to higher energy densities.
Replacing Coin Cell Batteries
With the higher energy density, TDK is positioning the new solid-state battery technology as an alternative to coin cell primary batteries. This is, in part, driven by EU battery regulations that restrict the use of disposable coin-cell batteries due to environmental concerns.
Aside from environmental concerns, coin cell batteries also have limitations when used in remotely deployed IoT devices that must function independently for years without access to external power sources. For many of these devices, energy harvesting technologies, combined with a small solid-state battery like CeraCharge, offer a sustainable power management solution that can operate independently for extended periods of time.
RF Beacon Application with Energy Harvesting
RF beacons transmit device identification and other data through local, low-power wireless networks like BLE 4.0. Beacons are increasingly used for device monitoring and tracking in smart home, medical, and industry 4.0 applications.
Energy storage for RF beacon applications
Beacons’ low operating power requirements allow them to use energy harvesting as a primary power source (solar, piezo, and thermoelectric). For these applications, the CeraCharge rechargeable solid-state battery works as an energy storage system, collecting and delivering power from the energy harvesting devices to operate the beacon.
All images used courtesy of TDK.
