文摘
The Li+-ion conductivity (蟽Li) in an electrolyte is an important parameter with respect to the performance of all-solid-state lithium-ion batteries (LIBs). However, little is known about how 蟽Li in a porous electrolyte differs from that in a highly dense electrolyte. In this study, the relationship between the bulk density (dbulk) and apparent 蟽Li (蟽Liapp) in a porous electrolyte of Li[Li1/3Ti5/3]O4 (LTO) was examined by theoretical and experimental approaches. The theoretical calculations demonstrated that dbulk and 蟽Li have a simple relationship irrespective of the radius of the spherical pores in the electrolyte; i.e., 蟽Li increases almost linearly with increasing 味, where 味 is the ratio of dbulk to the theoretical density. In fact, the observed 蟽Liapp of LTO, which was determined by four-probe alternating-current impedance measurements, increased with increasing 味. Hence, with this relationship, 蟽Liapp can be estimated by 味 and intrinsic 蟽Li (蟽Liint) and vice versa; such estimations provide critical information for determining the optimum compositions of composite electrodes for all-solid-state LIBs. The temperature dependence of 蟽Liapp in LTO and differences between the calculated and experimental results are also discussed.
