According to reports, Japan's TDK announced a breakthrough in the materials used in small solid state batteries, which is expected to significantly improve the performance of devices such as wireless headphones and smart watches. The energy density of this new material (i.e. the amount of energy that can be stored in a specific space) reaches 1,000 Wh/L, which is approximately 100 times that of TDK's current production battery. The battery developed this time will be made of all-ceramic materials, including oxide-based solid-state electrolytes and lithium alloy negative electrodes. TDK stated that the high energy storage capacity of this battery will enable it to achieve smaller size and longer life, while oxide materials provide high stability, thereby improving safety. This battery technology is designed for small batteries, replacing existing coin-shaped batteries, and is applied to watches and other small electronic appliances.