Stable cycling of lithium sulfide cathodes through strong affinity with a bifunctional binder

Improving lithium–sulphur batteries through spatial control of sulphur species deposition on a hybrid electrode surface

“…6). Figure 1e shows an SEM image and EDX mapping of an ITO glassy carbon hybrid electrode after one cycle of discharging to 1.7 V and then charging to 2.6 V. Although the nonpolar charging product (sulphur) has higher affinity with carbon compared with ITO 18,22,27 , the S elemental mapping still matched with the ITO mapping, indicating that more sulphur attaches to the ITO surface than to the carbon surface. This patterning distribution of sulphur after charging is related to the strong bonding between polysulphides and ITO.…”

“…From the recent theoretical understanding of the strong binding affinity of polysulphides, Li 2 S 2 and Li 2 S with polar surfaces 18,27 , we devised a model system for the spatial control of S species deposition using the coexistence of polar and nonpolar electrode surfaces by creating a regularly patterned ITO glassy carbon planar electrode (Fig. 1a).…”

“…Exciting progress has recently been made in trapping polysulphide species in high surface area carbon 10 , oxide and polymer [11][12][13] , in hollow structures [14][15][16] and with binders [17][18][19] . The pioneering work by the Nazar et al 1 on mesoporous carbon particles to encapsulate sulphur demonstrated the relatively high capacity of about 1,000 mAh g À 1 for 20 cycles 10 .…”

“…Recently, recognizing the coupling effect of polysulphide dissolution and large volume expansion has led to excellent cycle life up to 1,000 cycles based on the S-TiO 2 yolk shell nanoparticles and hollow S nanoparticles capped by polymer shells, which have predesigned empty space to accommodate volume expansion without fracturing the shell materials 25,26 . Another promising approach, based on the different chemical bonding nature of S (nonpolar) and Li x S (polar), is to design bifunctional binders to trap polysulphides 18,27 .…”

The dual actions of modified polybenzimidazole in taming the polysulfide shuttle for long-life lithium–sulfur batteries

“…18,19 The abundant nitrogencontaining functional groups bestow a great potential for chemical interactions with lithium PSs, similar to those between PBI and phosphoric acid. In addition, functional polymers with pyrrolic and pyridinic N such as polypropylene (PP) 20 and PVP, 21 as well as those with an ether bond such as PEO 22 and polysaccharides 23 could have important roles in capacity retention for Li-S batteries. 24 Herein, we develop a modified PBI (mPBI) polymer (Scheme 1) as a binder and a separator functional reagent for Li-S batteries.…”