Abstract The battery production reached 1,490 GWh in 2024, with Li-ion batteries comprising 80%. This growing demanded to a tightening of conditions regarding enhanced battery safety and environmental impact. A key component influencing safety is the separator, which electrically insulates the electrodes while enabling the transport of lithium ions. Polyvinylidene fluoride (PVDF) and its copolymer with chlorotrifluoroethylene (PVDF-CTFE) are promising alternatives to commercial separators. Their properties can be further improved using nanofillers to enhance mechanical strength, thermal resistance, electrochemical stability and ionic conductivity. This review emphasises that the selection of nanofillers can positively impact the safety-related properties of PVDF and contributes to the development of more efficient and durable energy storage solutions.