Bioinspired interfacial nanofluidic layer enabling high-rate and dendrite-free lithium metal negative electrodes.

Abstract

Lithium metal negative electrodes are highly promising for high-specific-energy batteries due to their low electrochemical potential and high capacity. However, dendrite growth due to limited Li⁺ transport at the interface hinder their performance and safety. Enhancing interfacial Li⁺ transport can prevent Li⁺ depletion and ensure uniform Li deposition. Herein, an artificial interphase layer inspired by the nanofluidic effects in organisms is developed. The artificial interphase layer exhibits nanofluidic ion transport behavior, offering a 3.6 times higher transference number and a 10⁷ times higher diffusion coefficient for Li⁺ compared to bulk solutions at a low Li salt concentration of 10^-6mol L^-1. Such selective Li⁺ conduction can effectively suppress dendritic growth, achieving a stable Li plating/stripping cycling at a current density of 200 mA cm^-2 and a high Coulombic efficiency of 99.7%. Consequently, the negative electrode-free Cu||LFP cell achieves 80.1% capacity retention after 200 cycles. Moreover, the Li||S full cell demonstrates high stability over 300 cycles with a 70.7% capacity retention at -20 ^°C and achieves a high specific energy of 505.1 Wh kg^-1 with designed capacity of 127.3 mAh (stack level). This nature-inspired interfacial nanofluidic layer design offers a promising strategy for developing high-rate, dendrite-free lithium metal negative electrodes.