 For the data analysis part, first, C(x) was calculated from the slope of the linear part in the measured (Q, V), by considering it as the non-breakdown part.And then, the first turning point (Qb(x), Vb (x)) was determined at the variant R2 value by linearly fitting C(x), which was considered as the threshold breakdown point.Finally, for any x∈[0, xmax], all the (Qb(x), Vb (x)) can be transferred into (QSC(x)- Qb(x), Vb (x)) as the breakdown points plotted in the V-Q cycle to calculate Eem of TENG.