The practical deployment of lithium-metal batteries (LMBs) with Ni-rich cathodes is limited by unstable electrode-electrolyte interfaces. Although LiNO3 is widely recognized as an effective additive for stabilizing these interfaces, its extremely low solubility in carbonate electrolytes (∼0.01 mg mL–1) severely limits practical use. Here, we introduce dehydrated sepiolite as a structurally simple, cost-effective, and multifunctional LiNO3 solubilizer for constructing robust electrode-electrolyte interfaces. Sepiolite, with its abundant polar oxygen sites and unique open nanochannels, weakens Li+–NO3– interactions, thereby increasing LiNO3 solubility to 13.0 mg mL–1 (over 1000-fold), while simultaneously scavenging H2O, HF, and transition-metal ions to mitigate parasitic reactions. These synergistic effects regulate interfacial chemistry and promote the formation of a Li3N-Li2O-LiF-rich interphase with high ionic conductivity, stabilizing the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode and enabling uniform lithium deposition. As a result, carbonate electrolytes incorporating the sepiolite-LiNO3 solubilizer (BE-Sep@NO3–) deliver a Coulombic efficiency of 99.0% in Li//Cu cells and stable cycling over 1200 h in Li//Li symmetric cells. Moreover, Li//NCM811 full cells retain 84.6% and 79.5% of their capacity at 0.5 C and 5 C after 400 cycles, respectively, while pouch cells with 50 μm lithium anodes achieve 82.5% capacity retention after 120 cycles with a high energy density of 375.1 Whkg–1. This work demonstrates that natural dehydrated sepiolite offers an environmentally friendly and scalable pathway to unlock the full potential of LiNO3 for enabling stable, high-energy LMBs.
Yang et al. (Thu,) studied this question.