Statistical Analysis: In this work, Young's modulus of the HBPFs with different intercalation ions was calculated by Equation (1) and was shown in Figure S12 (Supporting Information). Young's modulus and pretensions of each HBPF under different loads were calculated and the average was taken. The data including Young's modulus and pretensions are given in the form of mean ± standard deviation. The sample size is also listed in Figure S12 (Supporting Information). Statistical analysis was carried out using Microsoft Excel software.