Contactless Magnetoelectric Sensor Based on PVDF-TrFE and Metglass Laminates for Lithium-Ion Battery Current and Vibration Monitoring

The continuous increased energy density of lithium-ion batteries has led to growing concern about the safety issues, which has prompted the development of sensing technologies to achieve real-time state monitoring. However, the limited space in the lithium-ion battery pack presents great challenges of physical size and energy consumption for the existing current sensors. In the present work, a PVDF-TrFE/Metglass magnetoelectric laminate sensor with a minimized flexible structure and high temperature resistance was fabricated. By the in situ coating and polarization of the piezoelectric PVDF-TrFE on the magnetostrictive Metglass, the transition layer between them was eliminated to reduce the interfacial stress transfer losses. The well-formed interface resulted in high linearity over 0.981 and an excellent magnetoelectric response with a current sensitivity of 0.058 μV/mA. Additionally, the high Curie temperature of PVDF-TrFE provides the magnetoelectric sensor with high heat resistance over 120 °C. The PVDF-TrFE/Metglass magnetoelectric sensor can monitor the fluctuation of the lithium-ion battery current, enabling real-time detection and early warning of external short circuits and vibration impacts, presenting great value in lithium-ion battery safety monitoring.