All‐Solid‐State Batteries: New Cost‐Effective Halide Solid Electrolytes for All‐Solid‐State Batteries: Mechanochemically Prepared Fe³⁺‐Substituted Li₂ZrCl₆ (Adv. Energy Mater. 12/2021)

Abstract

In article number 2003190, Kyung‐Wan Nam, Yoon Seok Jung and co‐workers develop a new halide solid electrolyte, Fe3+‐substituted Li2ZrCl6, that is mechanically sinterable, (electro)chemical‐oxidation tolerant, and free of rare‐earth metals. The outstanding performance of the all‐solid‐state batteries using LiCoO2 and LiNi0.88Co0.11Al0.01O2 is enabled by the use of the newly developed halide superionic conductors.

Hydroborate Solid-State Lithium Battery with High-Voltage NMC811 Cathode

“…Only solid-state cells with a capacity retention of at least 80% after 100 cycles are considered. The shape of the symbol indicates the type of solid electrolyte: hydroborates (circles), ,, polymer and polymer composites (triangles), − sulfides (squares), ,,− halides and halide-sulfide bilayer (pentagons), − and oxides (diamonds). , Empty symbols indicate cells containing excess Li (oversized Li metal anodes or InLi alloy anodes). Full symbols indicate cells without excess Li (graphite and Ag–C anodes).…”

High-Conductivity Li2ZrCl6 Electrolytes via an Optimized Two-Step Ball-Milling Method for All-Solid-State Lithium–Metal Batteries

“…Yao et al successfully synthesized Li 2 ZrCl 6 with an even higher Li + conductivity of 1 × 10 –3 S cm –1 , but the preparation process is comparatively intricate. In this case, ball-milling cups were opened every 12 h, followed by manual homogenization, and the total time for ball-milling was 84 h. On the other hand, previous studies have shown that the ionic conductivity can also be improved by doping with metal ions. − Jung et al replaced partial Zr 4+ with In 3+ and Sc 3+ to increase the ionic conductivity of the annealed monoclinic-phase Li 2 ZrCl 6 from 7.1 × 10 –6 to 2.1 × 10 –3 S cm –1 . , Meanwhile, they found that Cr 3+ and V 3+ doping also can effectively enhance the ionic conductivity of Li 2 ZrCl 6 . However, ion doping may not only increase the cost of raw materials (like In 3+ and Sc 3+ ) or influence the environment (like Cr 3+ and V 3+ ) but also reduce the electrochemical stability of the electrolyte .…”

“…40,41 Meanwhile, they found that Cr 3+ and V 3+ doping also can effectively enhance the ionic conductivity of Li 2 ZrCl 6 . 42 However, ion doping may not only increase the cost of raw materials (like In 3+ and Sc 3+ ) or influence the environment (like Cr 3+ and V 3+ ) but also reduce the electrochemical stability of the electrolyte. 43 Furthermore, the intrinsic effects of ball-milling parameters on the structure and ionic conductivity of Li 2 ZrCl 6 have not been elucidated.…”

Prussian Blue‐Type Sodium‐ion Conducting Solid Electrolytes for All Solid‐State Batteries

“…Recent advances in the research and development of Na + superionic conductors include sulphide‐based solid electrolytes (SSEs) such as cubic Na 3 PS 4 (0.2mS cm −1 ), [14] Na 3 SbS 4 (1mS cm −1 ), [12] and Na 3−x P 1−x W x S 4 (8.8mS cm −1 ); [15] oxide‐based solid electrolytes (OSEs) like Na 3 Zr 2 Si 2 PO 12 (0.67mS cm −1 ) [11] and Na 2 Zn 2 TeO 6 (0.57mS cm −1 ); [16] and halide‐based solid electrolytes (HSEs) such as Na 2 ZrCl 6 (0.018mS cm −1 ), [13] Na 3−x Er 1−x Zr x Cl 6 (0.035mS cm −1 ), [17] and Na 3−x Y 1−x Zr x Cl 6 (0.066mS cm −1 ) [18] . Nevertheless, significant challenges remain to be addressed SSEs are unstable when exposed to water or oxygen in the air, resulting in the production of toxic H 2 S gas [10,19] . OSEs necessitate a high‐temperature sintering process and possess brittle mechanical properties, rendering them less suitable for cold forming and sintering [11,14,16] .…”

“…OSEs necessitate a high‐temperature sintering process and possess brittle mechanical properties, rendering them less suitable for cold forming and sintering [11,14,16] . HSEs often depend on rare and expensive central metals like Y, In, and Sc [19,20] . Moreover, synthesis methods for solid electrolytes (SEs) have been confined to high‐temperature solid‐state reactions or ball milling, presenting considerable barriers to practical implementation [14,16,21,22] .…”