Clay‐Originated Two‐Dimensional Holey Silica Separator for Dendrite‐Free Lithium Metal Anode

Abstract

Lithium metal anode is the ultimate choice to obtain next‐generation high‐energy‐density lithium batteries, while the dendritic lithium growth owing to the unstable lithium anode/electrolyte interface largely limits its practical application. Separator is an important component in batteries and separator engineering is believed to be a tractable and effective way to address the above issue. Separators can play the role of ion redistributors to guide the transport of lithium ions and regulate the uniform electrodeposition of Li. The electrolyte wettability, thermal shrinkage resistance, and mechanical strength are of importance for separators. Here, clay‐originated two‐dimensional (2D) holey amorphous silica nanosheets (ASN) to develop a low‐cost and eco‐friendly inorganic separator is directly adopted. The ASN‐based separator has higher porosity, better electrolyte wettability, much higher thermal resistance, larger lithium transference number, and ionic conductivity compared with commercial separator. The large amounts of holes and rich surface oxygen groups on the ASN guide the uniform distribution of lithium‐ion flux. Consequently, the Li//Li cell with this separator shows stable lithium plating/stripping, and the corresponding Li//LiFePO4, Li//LiCoO2, and Li//NCM523 full cells also show high capacity, excellent rate performance, and outstanding cycling stability, which is much superior to that using the commercial separator.

Emerging application of 2D materials for dendrite-free metal batteries

“…The modified separator demonstrates superior electrochemical performance, with a ten-fold longer lifespan in Zn//Zn symmetrical batteries. Recently, a Ti 3 C 2 T x MXene layer combined with a commercial GF separator has been reported, as shown in Figure 10D [177] . By virtue of the high conductive surface with abundant functional groups and the highly matched lattice contact with the Zn anode, the MXene can generate homogeneous surface electric field to achieve uniform zinc + deposition.…”

“…(D) Schematics illustrating the design of Ti 3 C 2 T x @glass fiber composite separator to stabilize the Zn anode. Reproduced with permission [177] . Copyright 2023, Elsevier.…”

Fast Li+ Transport Polyurethane-Based Single-Ion Conducting Polymer Electrolyte with Sulfonamide Side chains in the Hard Segment for Lithium Metal Batteries

“…In the temperature range of room temperature to 150 °C, all PUTA films maintained dimensional and morphological integrity without shrinkage or deformation (Figure S5), indicating good safety of the films. 39 As polyurethane-based polymer electrolytes, the samples degraded in two stages: first, the hard domains decomposed, followed by the decomposition of the soft phase. 40,41 Notably, the degradation of LiTFSI occurred at ∼340 °C, 42 which was partially superimposed with that of the PEG soft segment.…”