A highly ordered nanostructured carbon–sulphur cathode for lithium–sulphur batteries

Abstract

The Li-S battery has been under intense scrutiny for over two decades, as it offers the possibility of high gravimetric capacities and theoretical energy densities ranging up to a factor of five beyond conventional Li-ion systems. Herein, we report the feasibility to approach such capacities by creating highly ordered interwoven composites. The conductive mesoporous carbon framework precisely constrains sulphur nanofiller growth within its channels and generates essential electrical contact to the insulating sulphur. The structure provides access to Li+ ingress/egress for reactivity with the sulphur, and we speculate that the kinetic inhibition to diffusion within the framework and the sorption properties of the carbon aid in trapping the polysulphides formed during redox. Polymer modification of the carbon surface further provides a chemical gradient that retards diffusion of these large anions out of the electrode, thus facilitating more complete reaction. Reversible capacities up to 1,320 mA h g(-1) are attained. The assembly process is simple and broadly applicable, conceptually providing new opportunities for materials scientists for tailored design that can be extended to many different electrode materials.

Research Progress towards Understanding the Unique Interfaces between Concentrated Electrolytes and Electrodes for Energy Storage Applications

“…For example, the prioritory concerns of LIBs for hybrid electric vehicles (HEVs) or pure EVs are their energy density and safety properties. For storing renewable energy, reliabilty and cost are more important 2. While many research interests have been focused on materials chemistry,3 and electrolytes,4 the understanding of their derived interfaces has made much less progress due to the complexity of electrolyte decomposition in dynamic conditions and on various substrates with different surface properties.…”

Paper‐Based Electrodes for Flexible Energy Storage Devices

“…Such a “rate‐limiting step” has greatly impeded the commercialization of these electronics. In order to overcome this limiting factor, extensive efforts have been devoted to make flexible and high performance energy storage devices 12, 13, 14, 15, 16, 17, 18, 19…”

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

“…However, the insulating nature of sulfur (S) and its reaction products (i.e., Li 2 S), the large volume expansion from S to Li 2 S, along with the dissolution of lithium polysulfide intermediates (i.e., Li 2 S x , 4 ≤ x ≤ 8) into liquid electrolyte and the consequent shuttling effect between the anode and cathode, makes it generally display poor rate ability, limited cycle life and severe self‐discharge 1, 2, 3, 4, 5, 6, 7. Therefore, a variety of strategies have been pursued to circumvent the sulfur cathode problems, including optimization of organic electrolytes8, 9 and fabrication of sulfur‐conductive polymer composites10, 11 and sulfur–carbon‐based composites 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45. Among these approaches, porous‐carbon/sulfur composites12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 are more attractive because porous carbon can i...…”