Experimental confirmation of the model for microcracking during lithium charging in single-phase alloys

Indentation fracture toughness measurements yielded a KIC for Li4.4Sn equal to 0.8±0.2 MPa m1/2. From KIC, a critical crack length of 0.005 nm was determined for the stress generated due to the volume expansion as a result of Li charging into the Li4.4Sn alloy. The critical crack length was in excellent agreement with the predicted critical grain size for microcracking. This suggests that the model for predicting the critical grain size for microcracking during Li charging into brittle single-phase alloys is correct.