Preparation and performance of PVA/APP modified lithium battery separators
Polyvinyl alcohol(PVA)/ammonium polyphosphate(APP)modified separator was prepared through phase conversion method using APP with high degree of polymerization as flame retardant and PVA as film-forming framework material.The mechanical strength,wettability,thermal stability,microstructure,and electrochemical performance of the modified separator were then characterized.The influence of APP added on the performance of separator was further explored by assembling the separator into a lithium battery in a glove box filled with argon gas and evaluating its cycle rate performance.The results showed that when the PVA mass fraction was 10%in aqueous solution and the addition amount of APP was 8%(based on the mass of PVA),the modified separator exhibited excellent electrolyte wettability and thermal stability,with a liquid absorption rate of 215.0%and almost no shrinkage at 200℃.Meanwhile,the tensile strength of the modified separator reached 47.4 MPa.Moreover,after 50 cycles at 0.1 C,the specific discharge capacity was 143.2 mA·h/g,the coulomb efficiency was more than 97%,and the capacity retention rate reached 95.1%,while the capacity retention rate of the battery assembled by commercial lithium battery diaphragm was only 82.8%.
lithium separatorpolyvinyl alcoholammonium polyphosphatethermal resistanceflame retardantorganic electrochemistry and industry
NETL
NSTL
万方数据
维普
