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 porosity, liquid absorption, ionic conductivity, thermal stability, electrochemical stability window, cycling stability, and multiplicity of the assembled cells of the PU-based diaphragm were analyzed to verify the feasibility of a PU-based nanofiber diaphragm for lithium-ion batteries. 2. Experimental Materials and Methods 2.1.
To replace the traditional polyolefin microporous membrane, high-performance lithium-ion battery diaphragms have been prepared at the laboratory scale using dry and wet spinning, electrostatic spinning, and centrifugal spinning methods.
Analysis of Electrochemical Stability Electrochemical stability is an important performance parameter for lithium-ion battery diaphragms, which must maintain the stability of the electrolyte and electrode in terms of electrochemical properties to avoid degradation during the charge and discharge process.
A high electrochemical stability window facilitates the long-term stable operation of Li-ion batteries at a high voltage. To evaluate the electrochemical stability of the diaphragm, the potential range was set to 2.5 V–6.0 V to perform LSV tests on the Celgard 2400 and PU/PAN fiber diaphragms.
Conclusions A centrifugal spinning method was used to prepare a PU/PAN lithium-ion battery diaphragm by blending with different ratios of PAN. The properties of the PU/PAN lithium-ion battery diaphragms were characterized in this study.