The increase in the use of lithium-ion batteries demands that tests are faster, easier, cheaper and, if possible, non-destructive and non-perturbing. Electrochemical noise of Li batteries can be ultimately used as a non-invasive indicator of battery health and we have already shown that primary Li/MnO2 cells show increase in voltage noise after being shorted. On the other hand, if the battery is discharged slowly, voltage noise does not increase. Based on detailed investigations, morphological changes on metallic lithium can be detected by electrochemical voltage noise. This method can be seen as a preliminary step in the development of a sensor that will provide efficiency in detecting healthy batteries, either in production or during use [1] Lithium metal-based chemistries have a much higher capacity than currently available rechargeable chemistries because of the use of Lithium-aluminum alloy in rechargeable chemistries, as opposed to metallic Lithium. It is known that charging of lithium metal electrode results in the formation of dendrites. These dendrites can disrupt the separator separating the anode from the cathode, exposing the battery to a short circuit or even causing the battery to burn or explode. For this reason, the early detection of any potential dendrite formation is both academically interesting and industrially important. Some preliminary studies show that noise level increase drastically after charging. (Figure 1) Moreover, the anodes of the charged batteries were also examined with SEM and serious deterioration was observed in the anode of the battery after charging. (Figure 2) Just like noise measurements on non-rechargeable batteries with lithium chemistry exposed to short circuits, it is worthy to study on and develop an early detection method for lithium batteries that are prone to dendrites.
We will be presenting developments in electrochemical noise measurements and how they correlate to the charging of metallic lithium anodes and the importance of this diagnostic method in the industry and the possibilities it promises