Integrated microsensor for real-time microscopic monitoring of local temperature, voltage and current inside lithium ion battery

•Home-made three-in-one flexible micro sensor can be placed anywhere in a lithium ion battery.•Three-in-one flexible micro sensors are three functions, compactness, acid corrosion resistance, good temperature tolerance, quick response, real-time measurement and optional location.•In-situ diagnosis local temperature, voltage and current information of a lithium ion battery. The lithium ion battery overcharge may cause thermal runaway, even hazardous conditions like explosion, resulting in safety problem. High charge/discharge rate is required for 3C products like smart phone and tablet PC and electric vehicles, but it will cause steep rise of internal temperature of lithium ion battery, unstable voltage and current and safety problem. This study used micro-electro-mechanical systems (MEMS) to develop an integrated microsensor of temperature, voltage and current microsensors, embedded in the lithium ion battery for real-time microscopic monitoring of internal temperature, voltage and current. This integrated microsensor is characterized by quick response, real-time measurement and batch manufacturing.