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Although the Li metal has been gaining attention as a promising anode material for the next-generation high-energy-density rechargeable batteries owing to its high theoretical specific capacity (3860 mAh g–1), its practical use remains challenging owing to inherent issues related to Li nucleation and growth. This paper reports the fabrication of a lithiophilic multichannel layer (LML) that enables the simultaneous control of Li nucleation and growth in Li-metal batteries. The LML, composed of lithiophilic ceramic composite nanoparticles (Ag-plated Al2O3particles), is fabricated using the electroless plating method. This LML provides numerous channels for a uniform Li-ion diffusion on a nonwoven separator. Furthermore, the lithiophilic Ag on the Li metal anode surface facing the LML induces a low overpotential during Li nucleation, resulting in a dense Li deposition. The LML enables the LiNi0.8Co0.1Mn0.1O2|| Li cells to maintain a capacity higher than 75% after 100 cycles, even at high charge/discharge rates of 5.0 C at a cutoff voltage of 4.4 V, and achieve an ultrahigh energy density of 1164 Wh kg–1. These results demonstrate that the LML is a promising solution enabling the application of Li metal as an anode material in the next-generation Li-ion batteries.

Aqueous electrolytes with wide electrochemical stability windows are crucial for developing high-energy and safe lithium-ion batteries, and molecular crowding electrolytes, which use polyethylene glycol as a molecular crowding agent to inhibit water decomposition by forming strong hydrogen bonds, are promising candidates. However, the polymer increases the viscosity of the electrolyte and decreases the ionic conductivity. In addition, the electrode–electrolyte interfacial layer is ineffective to protect the electrodes from water decomposition at a low salt concentration. Here, a molecular crowding electrolyte is prepared by dissolving lithium bis(trifluoromethanesulfonyl)imide in a mixture of a small-molecular crowding agent (tetraethylene glycol) and H2O. Succinonitrile (SN) is introduced to widen the electrochemical stability window of the aqueous electrolyte up to 4.3 V and improve the ionic conductivity. SN also promotes the formation of a stable and uniform electrode/electrolyte interfacial layer on LiNi0.8Mn0.1Co0.1O2(NMC811), which can then be used as a cathode material. The fabricated NMC811/Li4Ti5O12full cell delivers a maximum energy density of 148 W h/kg, a Coulombic efficiency of 99.2%, and retains 72% of its initial capacity after 150 cycles at 0.2C with a positive/negative capacity ratio of 1.11. This paper introduces a viable strategy for developing high-energy-density aqueous batteries.