Environmental cell for inert atmosphere analysis
The environmental sample cell is fabricated from corrosion resistant stainless steel fitted with a 1mm-thick quartz observation window. Cell construction is gas tight providing a secure, inert gas environment for Raman analysis. Sample loading is easily performed in a glove box before loading the environmental cell onto the microscope stage. (Patent pending)
The size of the sample chamber is 10mm diameter by 1.5mm deep. The sample chamber region of the LIBcell can accommodate a range of sample thicknesses. For optimum analysis, position the sample such that it is close to the inner quartz surface, using spacers as necessary.
Environmental cell integrity
The long-term integrity of the LIBcell was determined using Lithium metal samples. When lithium metal is exposed to air the surface quickly is converted to a dull silver-gray color. In the presence of air the metal surface is converted to LiOH and then to Li2CO3. The spectra on the left show no change in the state of lithium after 24 hrs in the LIBcell under inert gas conditions.
Raman microspectroscopy can monitor and measure the condition of a charged anode, as shown in the left hand spectra. By performing such measurements in a LIBcell the reduction status of the electrode can be monitored over time while eliminating possible degradation due to environmental conditions.
Left: Measurement of charged electrode in Argon atmosphere in a LIBcell. Spectra illustrate that no electrode deterioration occurs over a 10-day time period following a charging cycle.
Right: Measurement of charged electrode exposed to air. This graph illustrates spectral changes reflecting electrode degradation resulting from exposure to air.