In situ Stress Transition Observation of Electrodeposited Sn-Based Anodes

3 In situ Stress Transition Observation of Electrodeposited Sn-Based Anodes 

In the case of the Sng2Ni3g electrode, the potential profile shows a slope that starts from 0.80 V vs. Li/Li and a plateau from 0.24 V vs. Li/Li. From the potential profile of the Sn electrode, the latter plateau can be assumed to be the formation of Li-rich Sn-Li alloy phases. 0.24 V vs. L /L is lower than the corresponding lithiation potential of the Sn electrode, which could indicate the higher overpotential associated with the electrochemical reaction to form Li-rich Sn-Li alloy phases in the Sn62Ni3g electrodes. The deflection profile shows only one flexion point of tensile stress increase which starts at 0.24 V vs. Unlike Sn, flexion points of the 

During the subsequent discharge process, the potential rises with accordance to the delithiation of Li-Sn alloys. Ex situ surface morphology observed in previous reports show that the electrodes crack during this delithiation process. In the deflection profile, a further drop in stress was observed for both electrodes. This is assumed to be due to cracking of the electrode, which is expected to relax the stress more quickly than the delithiation process does. Here, the phase transformation does not seem to cause any distinct effect on the stress transition. As the delithiation process was allowed to continue, the rapid relaxation of compressive stress stopped, and the stress became tensile. 

During the rest period after the delithiation, the potential dropped to a constant value with a transient step much shorter than 

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