A robust solid-electrolyte interphase (SEI) enabled by electrolyte addi-tive is a promising approach to stabilize Li anode and improve Li cycling efficiency. However, the self-sacrificial nature of SEI forming additives limits their capability to stabilize Li anode for long-term cycling. Herein, we demonstrate nanocapsules made from metal–organic frameworks for sus-tained release of -LiNO3 as surface passiva-tion additive in commercial carbonate-based electrolyte. The nanocapsules can offer over 10 times more -LiNO3 than the solubility of -LiNO3. Continuous supply of -LiNO3 by nano-capsules forms a nitride-rich SEI layer on Lianode and persistently remedies SEI during prolonged cycling. As a result, lifespan of thin Li anode in 50 μm, which experiences drastic volume change and repeated SEI formation during cycling, has been notably improved. By pairing with an industry-level thick -LiCoO2 cathode, practical Li-metal full cell demonstrates a remarkable capacity retention of 90％ after 240 cycles, in contrast to fast capacity drop after 60 cycles in -LiNO3 saturated electrolyte.