This cartridge incorporates ability to measure temperature near the electrode stack to the features of the Three Electrode Battery Test Cell. It is ideal choice when researcher wants to monitor temperature while performing reproducible electrochemical measurements of battery and supercapacitor materials under controlled compression. The installed temperature sensor is standard Pt100 resistance temperature detector (RTD). It ensures accurate and reliable readings in -50°C → +250°C range. It has a robust construction with the sensing element encased in a rigid 316 stainless steel sheath. The leads have a durable and flexible Teflon insulation and are screened for protection against electromagnetic interference. Leads connect to any 2, 3 or 4 wire Pt100 temperature measuring equipment. The temperature probe is located next to the reference electrode and is in direct contact with electrolyte, ensuring precise and real temperature reading from inside the cell.

The Battery Cartridge – Temperature Monitoring consists of upper and lower electrode plungers, separator lock ring, reference electrode punch and temperature probe (Pt100). The (default) electrode plungers are designed for planar electrodes with diameter of 18 mm and total sandwich thickness up to 2.5 mm. The diameter of separator shall be at least 2 mm larger than electrode diameter (max. 22 mm). The lock ring secures the separator in the electrode cartridge allowing easy and safe electrodes insertion, while ensuring accurate alignment. The upper and lower electrode plungers are available in various materials: 316L/317L Stainless Steel (default), copper, aluminium, nickel, gold plated nickel, etc. The punch-type reference electrode is installed from the side of the electrode cartridge. Thanks to sharp edged hole at the end of the pin the reference electrode (Li/Na/K etc.) can be easily punched from the metal foil and directly loaded into cell. The magnetic mount facilitates rapid assembly of the cartridge in the cell base For 2-electrode measurements the reference electrode feedthrough hole can be closed with the reference electrode punch. The battery cartridge elements are constructed with materials that are inert to the sample (Stainless steel 316L/317L and PEEK). It well fits aqueous (FKM O-Rings) and organic solvent (FFKM O-Rings) electrolyte requirements. Good electrical contact is ensured by gold plated pins. The battery cartridge can be effortlessly installed in the Three Electrode Battery Test Cell even when operating in the glove box, reducing possible human error to minimum.

**Application note ** This cell can be used for all common battery measurements, such as galvanostatic cycling, cyclic voltammetry or electrochemical impedance spectroscopy. Both liquid and solid-state electrolytes can be studied. Additionally, properties and performance of supercapacitor materials can be investigated. Various materials can be examined, including typical Li-ion electrodes (graphite, NMC, LTO, etc.) and other chemistries – sodium, magnesium, potassium etc. It can also be applied to measure the ionic conductivity of separators and electrolytes. The Pt100 temperature sensor adds option to collect real-time temperature data during measurement.