Hybrid polyion complex micelles enabling high-performance lithium-metal batteries with universal carbonates

Abstract

Lithium (Li) metal emerges as an anode for high-energy-density Li metal batteries due to their high theoretical capacity (3860 mAh g(-1)) and low electrochemical potential (-3.04V versus standard hydrogen electrodes). Nonetheless, the inherent instability of Li metal against conventional carbonate-based electrolytes (denoted as carbonates), causing unpredictable reactions and unstable interphase layers, precludes the commercialization of Li metal batteries. Herein, an innovative strategy-hybrid polyion complex micelle to enable high-performance Li metal anodes in carbonates is reported. Ionized LiNO3 cooperates with block copolymer (polystyrene-block-poly(2-vinyl pyridine) (S2VP)) micelles via electrostatic interaction and plants on the Li metal surface together. The union with S2VP and ionized LiNO3 can shut off from contact with the Li surface and carbonates, construct the unique solid electrolyte interface layers with a Li-ion conductivity gradient, and control Li morphology. S2VP/LiNO3-Li metal electrodes enable high-efficiencies over 100 cycles and even at high-temperature with universal carbonates. S2VP/LiNO3-Li//LiNi0.8Co0.1Mn0.1O2 full cells achieve long-stable cycling over 300 cycles under harsh test conditions: limited-excess Li (thickness of 40 and 100 mu m), high-areal capacity (4.0 mAh cm(-2)), and high-current density (4.0 mA cm(-2)). Moreover, a pouch-type full cell demonstrates commercial viability. This work provides new insights into enabling Li metal batteries with high-energy-density to adopt conventional carbonates.