Versatile Asymmetric Separator with Dendrite‐Free Alloy Anode Enables High‐Performance Li–S Batteries

Abstract

Lithium-sulfur batteries (LSBs) with extremely-high theoretical energy density (2600 Wh kg −1 ) are deemed to be the most likely energy storage system to be commercialized. However, the polysulfides shuttling and lithium (Li) metal anode failure in LSBs limit its further commercialization. Herein, a versatile asymmetric separator and a Li-rich lithium-magnesium (Li-Mg) alloy anode are applied in LSBs. The asymmetric separator is consisted of lithiated-sulfonated porous organic polymer (SPOP-Li) and Li 6.75 La 3 Zr 1.75 Nb 0.25 O 12 (LLZNO) layers toward the cathode and anode, respectively. SPOP-Li serves as a polysulfides barrier and Li-ion conductor, while the LLZNO functions as an "ion redistributor". Combining with a stable Li-Mg alloy anode, the symmetric cell achieves 5300 h of Li stripping/plating and the modified LSBs exhibit a long lifespan with an ultralow fading rate of 0.03% per cycle for over 1000 cycles at 5 C. Impressively, even under a high-sulfur-loading (6.1 mg cm −2 ), an area capacity of 4.34 mAh cm −2 after 100 cycles can still be maintained, demonstrating high potential for practical application.

A separator rich in SnF2 and NO3− directs an ultra-stable interface toward high performance Li metal batteries

“…Specifically, the separator functionalization is also a prospective technique for developing stable SEI, since it is in direct contact with the Li anode. [37][38][39][40][41][42][43] The beneficial constituents of the separator are transformed to form a protective layer of the Li anode in situ, thereby enhancing the performance of LMBs. Based on this principle, many materials including inorganic species, organic molecules and polymers are employed as functional layers for modifying the traditional polypropylene (PP) separator.…”

A ductile and strong-affinity network binder coupling inorganic oligomers and biopolymers for high-loading lithium–sulfur batteries

“…12–15 In addition, metal and metal compounds can accelerate the mutual transformation between polysulfides through electrocatalysis, so as to avoid the formation of a concentration gradient of polysulfides. 16–18…”

“…[12][13][14][15] In addition, metal and metal compounds can accelerate the mutual transformation between polysulfides through electrocatalysis, so as to avoid the formation of a concentration gradient of polysulfides. [16][17][18] As an important part of the sulfur cathode, the binder plays a very significant role in inhibiting the expansion of sulfur materials and anchoring polysulfides. One basic function of the binder is adhering active substances and conductive carbon onto the collector, so that the sulfur is closely connected with the conductive carbon.…”

Enhanced Li–S Battery Performance Boosted by a Large Surface Area Mesoporous Alumina-Based Interlayer

“…1−5 On the other hand, the Li−S battery faces a series of challenges, among which the notorious "shuttle effect" is the key issue hindering the commercialization of Li−S batteries at present. 6,7 To tackle the "shuttle effect", in the past decade, numerous studies have been conducted on the design and fabrication of advanced materials for cathodes, 8,9 separators, 10,11 electrolytes, 12,13 and binders. 14,15 In recent years, construction of functional interlayers for Li−S batteries have been recognized as a viable and effective mean to suppress the "shuttle effect".…”

“…Owing to extremely high theoretical energy density up to 2600 W h kg –1 (5 times higher than current lithium-ion batteries) and low cost, a lithium–sulfur (Li–S) battery was considered as a promising candidate for a secondary battery system. − On the other hand, the Li–S battery faces a series of challenges, among which the notorious “shuttle effect” is the key issue hindering the commercialization of Li–S batteries at present. , To tackle the “shuttle effect”, in the past decade, numerous studies have been conducted on the design and fabrication of advanced materials for cathodes, , separators, , electrolytes, , and binders. , In recent years, construction of functional interlayers for Li–S batteries have been recognized as a viable and effective mean to suppress the “shuttle effect”. , Owing to high conductivity that is beneficial for electrochemical reaction, carbon materials have attracted much attention for interlayer construction . However, suppression of the “shuttle effect” using the nonpolar carbon materials is not satisfactory due to the weak interaction of carbon with polysulfides, especially in the long-term charge–discharge cycles .…”