Related Experiment Video
Updated: May 11, 2026

Solid-state Graft Copolymer Electrolytes for Lithium Battery Applications
Published on: August 12, 2013
Fast, reversible lithium storage with a sulfur/long-chain-polysulfide redox couple
Yu-Sheng Su1, Yongzhu Fu, Bingkun Guo
1Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, USA.
Abstract:
The cathodic reactions in Li-S batteries can be divided into two steps. Firstly, elemental sulfur is transformed into long-chain polysulfides (S8 ↔ Li2S4), which are highly soluble in the electrolyte. Next, long-chain polysulfides undergo nucleation reaction and convert into solid-state Li2S2 and Li2S (Li2S4 ↔ Li2S) by slow processes. As a result, the second-step of the electrochemical reaction hinders the high-rate application of Li-S batteries. In this report, the kinetics of the sulfur/long-chain-polysulfide redox couple (theoretical capacity=419 mA h g(-1)) are experimentally demonstrated to be very fast in the Li-S system. A Li-S cell with a blended carbon interlayer retains excellent cycle stability and possesses a high percentage of active material utilization over 250 cycles at high C rates. The meso-/micropores in the interlayer are responsible for accommodating the shuttling polysulfides and offering sufficient electrolyte accessibility. Therefore, utilizing the sulfur/long-chain polysulfide redox couple with an efficient interlayer configuration in Li-S batteries may be a promising choice for high-power applications.
Related Concept Videos
Batteries and Fuel Cells
Types of Reversible Electrodes
Weak Acid Solutions
Voltaic/Galvanic Cells
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
Ionic Bonding and Electron Transfer
Formation of Complex Ions

