We have developed dilute ether electrolytes by adding a small amount of NO3 -anions for long-term cycling of LMBs under voltages as high as 4.3 V, which break the long-standing voltage limitation for dilute ether electrolytes. Our combined experimental and modeling results have uncovered that accumulation of added NO3 -in the inner layer of EDL at the cathode is important to squeeze out DME molecules at the cathode and thus suppresses the ether reactivity.