The diaphragm of a lithium-ion battery has important functions, such as preventing a short circuit between the positive and negative electrodes of the battery and improving the movement channel for electrochemical reaction ions.
The zinc borate modified diaphragm was used as the structural-functional ceramic composite diaphragm, and the zinc borate and PVDF were prepared at a mass ratio of 90:10, and the ordinary diaphragm and the zinc oxide modified diaphragm were used as comparison samples. The battery electrolyte was 1 M LiPF6 in EC/DEC (1:1 vol ratio).
In addition, carbon materials are used as modified diaphragms, which play a certain role in accelerating redox kinetics and improving the electrochemical performance of lithium-sulfur batteries because of their good electrical conductivity, mechanical loading, and heat resistance [ 27 ].
The results show that the zinc borate modified diaphragm increases the lithium-ion migration number of the battery. This is because the Lewis acid sites of zinc borate can absorb anions in the battery system, and the increase in the migration number of lithium ions will help improve rate performance .
The lithium-ion migration numbers of ZnB modified diaphragm are 0.41, while the lithium-ion migration numbers of ZnO modified diaphragm and routine diaphragm are 0.3 and 0.21. When the battery is working, the charge transfer rate of lithium ions reflects the charging and discharging characteristics of the battery.
A simple sol-gel coating method is used to uniformly deposit a thin layer of titanium dioxide on the PP diaphragm. The LiFePO 4 /Li battery with PP@TiO 2 diaphragm has a high capacity of 92.6 mAh g −1 at 15C . Gu et al. used nano-ZnO to prepare a new type of porous cross-linked diaphragm.