Monitoring the dynamic chemical and thermal state of a cell during operation is crucial to making meaningful advancements in battery technology as safety and reliability cannot be compromised. Here we demonstrate the feasibility of incorporating optical fibre Bragg grating sensors into commercial 18650 cells. By adjusting fibre morphologies, wavelength changes associated with both temperature and pressure are decoupled with high accuracy, which allows tracking of chemical events such as solid electrolyte interphase formation and structural evolution. We also demonstrate how multiple sensors are used to determine the heat generated by the cell without resorting to microcalorimetry. Unlike with conventional isothermal calorimetry, the cell’s heat capacity contribution is readily assessed, allowing for full parametrization of the thermal model. Collectively, these findings offer a scalable solution for screening electrolyte additives, rapidly identifying the best formation processes of commercial cells and designing battery thermal management systems with enhanced safety.

由于安全性和可靠性不会受到损害，因此在运行期间监视电池动态化学和热状态对于电池技术取得有意义的进步至关重要。在这里，我们演示了将光纤布拉格光栅传感器并入商用18650电池的可行性。通过调整纤维的形态，与温度和压力相关的波长变化可以高精度地解耦，从而可以跟踪化学事件，例如固体电解质的界面形成和结构演变。我们还演示了如何使用多个传感器来确定电池产生的热量，而无需借助微量量热法。与传统的等温量热法不同，可以轻松评估电池的热容量贡献，从而可以对热模型进行完全参数化。