Fast Formation to Decrease Manufacturing Cost?

Formation in lithium-ion battery manufacturing typically involves low-rate charge-discharge cycles to establish a stable electrode/electrolyte interfaces, a time-consuming process. Our findings on Li-rich layered oxide (LLO) cathodes challenge the necessity of conventional formation, which can even shorten battery lifespan. Fast formation, on the other hand, reduces production cost and enhances capacity and stability. Multi-scale synchrotron-based techniques show that residual Li ions after the initial charge are critical for subsequent structural evolution and cycling performance. Deep Li de-intercalation causes severe structural degradation and capacity loss due to the inherently fragile Li-deficient matrix, while residual Li ions from fast formation enhance reversibility through a self-pinning effect, preventing pernicious lattice deformation and reinforcing the ion storage framework. Adjusting the initial charge current density from 0.2 C to 2 C improves reversible capacity by 20% and cycle life by over 36% simultaneously. This approach can also be extended to other electrode systems, providing new insights for more efficient battery production. [ Nature 2025, in press]