Manipulating surface reactions in lithium–sulphur batteries using hybrid anode structures

Abstract

Lithium-sulphur batteries have high theoretical energy density and potentially low cost, but significant challenges such as severe capacity degradation prevent its widespread adoption. Here we report a new design of lithium-sulphur battery using electrically connected graphite and lithium metal as a hybrid anode to control undesirable surface reactions on lithium. Lithiated graphite placed in front of the lithium metal functions as an artificial, self-regulated solid electrolyte interface layer to actively control the electrochemical reactions and minimize the deleterious side reactions, leading to significant performance improvements. Lithiumsulphur cells incorporating this hybrid anodes deliver capacities of 4800 mAh g À 1 for 400 cycles at a high rate of 1,737 mA g À 1 , with only 11% capacity fade and a Coulombic efficiency 499%. This simple hybrid concept may also provide scientific strategies for protecting metal anodes in other energy-storage devices.

Biomass-derived renewable carbon materials for electrochemical energy storage

“…All of the aforementioned drawbacks result from the insulating nature of sulfur, dissolution of reaction intermediates (lithium polysulfides) and large volume variation between sulfur and sulfides during electrochemical reaction process [130]. To date, various approaches, such as developing new electrolytes [131][132][133], modifying the separator [134], protecting lithium anode [135], as well as designing new configuration [136,137], have been adopted to mitigate the 'shuttle effect' of polysulfides and prolong cyclic life. Particularly, to improve the practical lithium-sulfur performance, many efforts have been devoted to developing advanced sulfur cathodes, including adding advanced binder or hybridizing sulfur with conductive host to improve conductivity, modifying surface chemistry or introducing metal oxides with strong adsorption to retard the dissolution of polysulfides, inserting interlayer to manipulate the 'shuttle effects' of polysulfides or designing nanostructure (yolk-shell or hollow) to accommodate the volume change during electrochemical reaction process [138].…”

Sulfur–Graphene Nanostructured Cathodes via Ball-Milling for High-Performance Lithium–Sulfur Batteries

“…To overcome the above-mentioned obstacles, carbon based materials with various hierarchical structures, including meso-/micro-porous carbons [6][7][8][9][10][11] , hollow carbon spheres [12][13][14] , carbon nanotubes/nanofibers [15][16][17][18][19] , graphene derivatives [20][21][22][23][24][25][26][27][28][29][30] , and flexible carbon membranes 31 6 C with a low decay rate of 0.039% per cycle over 1500 cycles) 25 , a sulfur-graphene composite with ~ 63.6 wt% sulfur uniformly coated on graphene through reduction of GO and concomitant sulfurization (440 mAh g -1 after 500 cycles at 0.75 C) 22 , and polyvinylpyrrolidone (PVP)-encapsulated hollow S nanospheres (i.e., S@PVP nanospheres) from the reaction of Na2S2O3 and…”

“…Thus, the ball-milling technique effectively combines both the physical and chemical routes into one-step process for low-cost, scalable, and eco-friendly production of highly-efficient LSB 11,25,28,37 attributable to its 3D porous 'sandwich-like' structure (vide infra), coupled with the newlydiscovered 'spin-effect' induced by S-doping, leading to enhanced ionic conductivity and lithium insertion/extraction during the discharge-charge process.…”

Leaf‐Like Graphene‐Oxide‐Wrapped Sulfur for High‐Performance Lithium–Sulfur Battery

“…Based on the result of self‐discharge investigation, leaf‐like GO/S composites can largely limit the self‐discharge of Li–S battery. However, to further reduce the self‐discharge of Li–S batteries, a synergy of methods are still needed such as optimizing the electrolyte,7, 8 designing new battery structure,52, 53 protecting Li anode,54, 55 and spatially controlling sulphur species deposition 56. For comparison, conventional GO/S composite was synthesized and investigated as electrode for Li–S battery (Figure S9, Supporting Information).…”