A Sacrificial Additive Strategy: Integrates Scavenging and Byproduct Utilization for High‐Voltage Lithium Batteries

ABSTRACT Lithium‐ion batteries dominate the portable energy storage landscape, yet their energy density needs to be improved to meet the demands from advanced applications. Although sacrificial additives can effectively elevate the operating voltage of batteries, the functional potential of their chemical by‐products has been largely overlooked. Here, we report trimethylsilyl trifluoromethanesulfonate (TMSOTF) as a multifunctional additive. It not only scavenges detrimental agents but also directs the by‐products to form a protective interphase. This strategy enables LiCoO ₂ ||Li cells to maintain 79.82% capacity after 200 cycles (3.0–4.65 V) with only 1 wt% additive, a substantial improvement over conventional electrolytes. This work pioneers a byproduct‐utilization paradigm for designing next‐generation sacrificial additives.