New material doubles battery lifespan while harvesting energy from movement
Researchers have engineered a graphene-enhanced membrane that dramatically improves both energy storage and power generation. The advance could extend electric vehicle battery life by years while enabling devices to generate electricity from vibration—opening new markets in self-powered wearables and IoT sensors.
Originaltitel: Graphene-PVDF composite membrane for piezoelectric nanogenerators and lithium-ion batteries
<p>Herein, we introduce a composite membrane comprising polyvinylidene fluoride/graphene nanosheets (PVDF/graphene) for applications in piezoelectric nanogenerators (PENGs) and lithium-ion batteries (LIBs), where the graphene nanosheets play a vital role in enhancing the piezoelectric properties, surface energy, and porosity. A comparative analysis of the pure PVDF and the PVDF/graphene is conducted to evaluate their piezoelectric performance and suitability as separators in LIBs. The PVDF/graphene composite membrane produced a significantly improved piezoelectric output of ∼10.8 V under a force of 75 N, while the pure PVDF membrane exhibited only ∼3.7 V under the same conditions. Additionally, the Li//PVDF/graphene//graphite half-cell retained ∼81.3% of its specific capacity and maintained a coulombic efficiency of over 99.2% after 100 cycles at a 0.2 C rate. In contrast, the Li//pure PVDF//graphite half-cell retained only ∼48.6% specific capacity. Furthermore, in a full-cell configuration, the graphite//PVDF/graphene//LCO cell demonstrated excellent stability, retaining ∼88% of its specific capacity after 50 cycles, whereas the cell with pure PVDF membrane retained only 38%. Therefore, the PVDF/graphene nanosheet composite membrane has the potential to be used as a piezoelectric membrane in PENGs and as a separator in LIBs.</p>