Chip-Sized Solid-State Battery Opens Door to New IoT Era

The Next-Generation Solution to Limitations of Conventional Lithium-Ion Batteries

It is no exaggeration to say that as we enter the IoT era—where almost everything is connected to the Internet—high battery performance is essential, in addition to compactness and improved communication capabilities, for various smart devices to become even more prevalent. Lithium-ion batteries, which have high energy density, are commonly used today in various electronic devices such as laptops, smartphones and wireless earbuds, and are increasingly utilized in drones, electric bikes and EVs (electric vehicles). However, because lithium-ion batteries made with flammable, organic-solvent electrolytes carry the risk of leakage and fire, there has been an increasing demand from IoT device makers for the development of safer and more reliable solid-state batteries containing stable electrolyte material. The battery market is expected to grow further, as large-capacity batteries like those in EVs are also expected to be replaced by solid-state batteries in the future.

Global Market Size and Forecast of Small All-Solid-State Lithium-Ion, Thin Type Batteries

Source: Created based on Global Next-Generation Batteries Market: Key Research Findings 2019 by Yano Research Institute Ltd.,

Conventional Lithium-Ion Batteries vs. Solid-State Lithium-Ion Batteries

Features of CeraCharge, the Solid-State SMD Battery Pioneered by TDK

TDK successfully commercialized the world’s first solid-state SMD (Surface Mount Device) battery—CeraCharge, as the development of solid-state batteries continue to be pursued by companies worldwide. CeraCharge was created based on TDK’s advanced multilayer ceramic technologies and has the advantage of being suitable for mass production. Its solid ceramic electrolyte eliminates the risk of leakage and fire, while other practical properties include: nominal voltage 1.5V, capacity 100μAh, and an operating temperature range of -20˚C to 80˚C. Additionally, its SMD-type design allows for easy battery placement, which helps to keep assembly costs down. Its advantages in size, safety and long life offer great possibilities for implementation in IoT devices to be used in a variety of settings.

Cross Section of CeraCharge™ Solid-State Battery (Schematic Diagram)

Adoption in Cooking Thermometers

CeraCharge—the safe, chip-sized solid-state battery, is working its way into a wide range of IoT products. One such application is a cooking thermometer product launched in December 2020. This new product—a 15cm metal thermometer probe from CookPerfect, a Danish company that manufactures a line of cooking thermometers—is equipped with five temperature sensors, a BLE (Bluetooth Low Energy)^*2 communication module, and TDK’s CeraCharge. The internal temperature of meat being cooked inside an oven can be monitored in real time from a smartphone by simply inserting this probe. This breakthrough product enables one to cook meats like Christmas roasts at perfect temperatures.

Martin Kloster, Co-Founder and Managing Director of CookPerfect, says: “When we began designing CookPerfect in 2016, battery technology was simply not available that would allow measuring at 5 points, run complex algorithms, and could be built into the unit. But with CeraCharge, we could create the first ‘true wireless’ thermometer.” Kloster says reliability and safety are very important, as these thermometers are inserted directly into food and used in high-heat ovens and grills. “There must never be any chemical leakage. We also needed a high operating temperature range that could withstand usage inside ovens. The fact that CeraCharge has no risk of leakage due to its solid form, is small enough to be installed into a 3.7mm-diameter unit, and can withstand up to 85˚C—were major deciding factors in choosing it for our product.”

CookPerfect’s Wireless Meat Thermometer

The advent of a full-scale IoT society is on the horizon as devices with various sensors—like this cooking thermometer which combines temperature sensors with communication capabilities—continue to proliferate. Along with the growing need for batteries in various sizes and specifications, CeraCharge is currently being considered for integration into a wide variety of devices, including real-time clocks (RTC)^*3 for smart meters, wearables, and smart sensors.

TDK, the first in the world to commercialize solid-state batteries, continues to work on expanding its lineup of products with increased miniaturization and capacities to cover a wider range of applications. CeraCharge will continue to support the rapidly expanding IoT market.

CeraCharge™ Solid-State Battery