Salt-in-Salt Reinforced Carbonate Electrolyte for Li Metal Batteries

A universal salt-in-salt strategy is proposed to boost LiNO₃ solubility in carbonate electrolytes using multivalent salt carrier. The NO₃⁻-containing anion complexes and multivalent cations as interphase adsorbing components promote the anion-derived SEI formation. The designed electrolyte presents a superior Li CE of 99.7 % and enables the NMC811 full cells with N/P ratio of 1.92 to achieve 84.6 % capacity retention after 200 cycles.