The ambition of INSTABAT is to monitor in operando key parameters of a Li-ion battery cell, in order to provide higher accuracy States of Charge, Health, Power, Energy and Safety (SoX) cell indicators, and thus allowing to improve the safety and the Quality, Reliability and Life (QRL) of batteries. To achieve this goal, INSTABAT will develop a proof of concept of smart sensing technologies and functionalities, integrated into a battery cell and capable of: • performing reliable in operando monitoring (time- and space-resolved) of key parameters (temperature and heat flow; pressure; strain; Li+ concentration and distribution; CO2 concentration; “absolute” impedance, potential and polarization) by means of: (i) four embedded physical sensors (optical fibers with Fiber Bragg Grating and luminescence probes, reference electrode and photo-acoustic gas sensor), (ii) two virtual sensors (based on electro-chemical and thermal reduced models), • correlating the evolution of these parameters with the physico-chemical degradation phenomena occurring at the heart of the battery cell, • improving the battery functional performance and safety, thanks to enhanced BMS algorithms providing in real-time higher accuracy SoX cell indicators (taking the measured and estimated parameters into consideration). Main results will be: (1) proof of concept of multi-sensor platform (cell prototype equipped with physical/virtual sensors, and associated BMS algorithms providing SoX cell indicators in real-time); (2) demonstration of higher accuracy for SoX cell indicators; (3) demonstration of improvement of cell functional performance and safety through two use cases for EV applications; (4) techno-economic feasibility study (manufacturability, adaptability to other cell technologies...). INSTABAT smart cells will open new horizons to improve cell use and performances (e.g. by reducing ageing, allowing the decrease of safety margins, triggering self-healing, facilitating second life, etc.).