Gas analysis with pressure transducer and on-line electrochemical mass spectrometer (OEMS) with ATO
For the in-situ gas analysis during discharge and charge of the Li-O2 battery with ATO-based cathodes and Vulcan carbon cathodes, a coupled system with a direct pressure/vacuum capacitance manometer (Baratron, MKS instruments, in the following referred to as "Baratron") and our On-line Electrochemical Mass Spectrometer (OEMS) is used. The OEMS cell is equipped with a capillary leak connected to the OEMS (E) and two valves (A and B) for gas flushing, one of which (A) is connected to the gas line and the second one to the vacuum pump (B). The Baratron is connected to the OEMS cell by a ¼'' stainless steel tubing. The measurement procedure with the coupled gas analysis system first involves the OEMS cell assembly inside an Ar-filled glove box (H2O < 0.1 ppm, O2 < 0.1 ppm). Subsequently, the cell is connected to the pressure transducer unit using cutting-ring fittings (VCR). The whole assembly is then joined to a vacuum pump, and first, the pressure transducer unit (volume VB) and the connecting unit (VT) are evacuated (valves C and D open, valves A, B, and E closed) for 10 min. After connecting the cell to the gas line, the connection between Baratron and OEMS cell is opened such that the Ar gas in the cell headspace expands to the whole system (VB + VT +VC; valves B and C open, valves A, D, and E closed). Then the system is flushed with O2 (99.999%, Westfalen, Germany) for 2 min at a flow rate of 80 cm (valves A-D open, valve E closed). After that, the O2-filled cell is discharged while recording the O2 consumption as a pressure decrease with the Baratron (valves B and C open, valves A, D, and E closed). When the discharge to 2 V vs. Li/Li+ is finished, the system is flushed with Ar to remove the remaining O2 (valves A-D open, valve E closed) and to have a pure Ar background for monitoring the gas evolution during charge by OEMS. Only gases from the cell head space are sampled by OEMS through the capillary leak (valve E open, valves A-D closed) during charge. If you are looking for high quality, high purity, and cost-effective ATO, or if you require the latest price of ATO, please feel free to email contact mis-asia.