Aqueous Zn-ion batteries (AZIBs) ensure unparalleled safety for large-scale energy storage applications. However, developing highly reversible zinc metal anodes with finite capacity is a prerequisite to realizing the performance characteristics...

Despite their potential, Li metal batteries have a poor cycle life due to being chemically unstable and having a fragile solid-electrolyte interphase (SEI). The SEI forms significant crack formations during cycling, resulting in Li dendrite growth. Such dendrites continuously consume electrolytes and deteriorate the cycle lifetime of Li-metal batteries. [2] Electrolyte engineering has been used widely to suppress Li dendrites by improving the formation of SEI. [3] In 2013, salt-type additives such as CsPF 6 , as proposed by Zhang et al. [4] can stabilize the Li-metal surface based on a self-healing electrostatic shield mechanism; the cation component creates a positive shielding layer near the dendrite's nucleation point and a repulsive interaction between the Li ions. The shielding cations push the Li ions to adjacent regions, inducing a smooth Li surface. However, these types of shielding cations are co-deposited with Li at a high current density, impairing the protective effect. [3a,5] Recently, ionic liquid (IL) has received great attention as a promising electrolyte additive for stabilizing Li-metal anodes due to a synergistic effect of the cation as a shielding agent [6] and the anion as an SEI-improving agent; [7] the cation enables uniform Li deposition, while anion builds a robust SEI. Recent advances in IL have revealed that a nonpolar alkyl chain to cations is a lithiophobic barrier that impedes Li ion transport toward the protruding tips. [6] Moreover, the IL cations modified with asymmetrically extended alkyl chains have been conceived as the most effective shielding agent for a uniform Li plating. [6a] Despite their potential to modulate Li deposits smoothly, research on the rational design of ILs for optimal control of Li plating has not been thoroughly developed and requires further improvement to achieve longlasting practical Li-metal batteries.Herein, we present a new design for IL additives and their self-assembly on Li protuberant tips for stable and high-performance Li-metal batteries. Uniquely, we introduce symmetric lithiophobic alkyl chains to pyrrolidium cations (Pyr + ). Pyrrolidium is a promising shielding moiety for Li-metal anodes because it can preferentially assemble near protuberances by the electric field and its reduction potential is lower than that of the Li ions (−3.04 V vs standard hydrogen electrode, SHE). [8] Modulating lithium metal deposition is vital for the realization of stable and energy-dense Li-metal batteries. Ionic liquid (IL) has been regarded as a promising electrolyte additive for a uniform Li deposition because its cation moiety forms a lithiophobic protective layer on Li protuberant tips. Despite recent advances in ILs forLi metal batteries, rational designs for IL additives are still in their infancy, and further improvement is required. Here, a new class of self-assembled protective layer based on the design of a new IL molecule enabling high-performance Li-metal batteries is reported. For the first time, symmetric design of lithiophobic side chain...

Nicotinamide adenine dinucleotide (NAD+) is one of the most well‐known redox cofactors carrying electrons. Now, it is reported that the intrinsically charged NAD+ motif can serve as an active electrode in electrochemical lithium cells. By anchoring the NAD+ motif by the anion incorporation, redox activity of the NAD+ is successfully implemented in conventional batteries, exhibiting the average voltage of 2.3 V. The operating voltage and capacity are tunable by altering the anchoring anion species without modifying the redox center itself. This work not only demonstrates the redox capability of NAD+, but also suggests that anchoring the charged molecules with anion incorporation is a viable new approach to exploit various charged biological cofactors in rechargeable battery systems.

We unveil that the conformational change of a single organic molecule during the redox reaction leads to impressive battery performance for the first time. We propose the model material, a phenoxazin-3-one derivative, as a new redox-active bioinspired single molecule for the Li-ion rechargeable battery. The phenoxazin-3-one cathode delivered a high discharge capacity (298 mAh g–1) and fast rate capability (65% capacity retention at 10 C). We elaborate the redox mechanism and reaction pathway of phenoxazin-3-one during Li+-coupled redox reaction. The molecular structure alteration of phenoxazin-3-one during the lithium-coupled electron transfer reaction enables strong π–π interaction between 2Li-phenoxazin-3-one and carbon, which was evidenced by operando Raman spectroscopy and density functional theory calculation. Our work provides in-depth understanding about the conformational molecular switch of the single molecule during Li+-coupled redox reaction and insight into the design of a new class of organic electrode materials.

Nicotinamide adenine dinucleotide (NAD+) is one of the most well‐known redox cofactors carrying electrons. Now, it is reported that the intrinsically charged NAD+ motif can serve as an active electrode in electrochemical lithium cells. By anchoring the NAD+ motif by the anion incorporation, redox activity of the NAD+ is successfully implemented in conventional batteries, exhibiting the average voltage of 2.3 V. The operating voltage and capacity are tunable by altering the anchoring anion species without modifying the redox center itself. This work not only demonstrates the redox capability of NAD+, but also suggests that anchoring the charged molecules with anion incorporation is a viable new approach to exploit various charged biological cofactors in rechargeable battery systems.