Mask‐Based Separator with Sustained‐Release LiNO₃ as Dendrite Growth Barrier for Potassium Metal Battery

Abstract

Separators with low-cost, superior mechanical properties, such as nanofiber materials, are considered a viable option for solving the dendritic problem in alkali metal batteries. Consuming the dendrites rather than blocking them underpins the long-life stable cycle performance of the cell. Herein, a five-layer structural separator (LiNO 3 @PVDF@mask) is presented, in which a mask is used as a framework and the polyvinylidene fluoride (PVDF) layer loaded with LiNO 3 can generate a passivation layer by reacting with K dendrites. In the case of potassium metal batteries, for example, the LiNO 3 @PVDF@mask separator has excellent mechanical properties that can effectively cope with the hazards caused by the K dendrite. In addition, sustained-release LiNO 3 can react with penetrated K dendrites to form inactive substances like KNO 3 and K 2 O, blocking further dendrite growth. Importantly, the LiNO 3 @PVDF@mask separator uses a low-cost abundant mask and possesses excellent wettability of electrolyte with a reduced amount of liquid electrolyte, enabling one to further iron out cost problems. This study opens up a new direction for research and contributes to practical applications of flexible devices for rechargeable alkaline metal batteries.

Hydrogen-bond regulation in organic/aqueous hybrid electrolyte for safe and high-voltage K-ion batteries

“…However, safety concerns arising from the use of organic electrolytes always remain, which may lead to catastrophic fires or explosions and pose a great threat to life. 5–8 In pursuit of more reliable and affordable energy storage, aqueous batteries with high safety, low cost, and facile assembly conditions are attracting renewed attention in recent decades. 9–13 Nonetheless, due to the inherent thermodynamic properties of water, the narrow electrochemical stability window (ESW) of aqueous electrolytes is a knotty and long-unresolved problem, which not only limits the energy density of aqueous batteries but also limits the choice of electrode materials.…”

Recent advances in rational design for high-performance potassium-ion batteries

“…It is noteworthy that some progress has been made in potassium–metal battery separators, which may provide design ideas for subsequent PIB separators. Mou et al 686 used a face mask as the separator body and added a LiNO 3 @PVDF layer on it. The reaction of LiNO 3 with K dendrites consumes the dendrites and forms a passivation layer that prevents the dendrites from puncturing the separator, thereby greatly improving safety.…”

In Situ-Formed Fe-Based Protective Layer for Dendrite-Free K Metal Anode

“…Various strategies such as electrolyte regulation, , separator modification, − and artificial SEI construction have been proposed to protect the potassium metal anode effectively. The artificial SEI strategy is a simple and effective interface regulation strategy among these strategies.…”