Development of novel energy storage systems with improved efficiency and reduced cost is highly desired due to the emerging storage applications, such as grid storage system. Lithium-sulfur battery (Li-S) has been recognized as one promising system beyond conventional Li-ion system due to its high gravimetric energy density and low material cost, which is superior to most of current Li-ion batteries.

Unfortunately, the further commercialization was prohibited by some major issues of Li-S system, such as shuttling effect, which are still not fully surpassed after years’ development. In addition, conflict also exists between the overall electrochemical performance and active material loading. Other issues such as electrolyte amount are also critical. Both chemistry and engineering research and development are necessary to address all those issues that delay the large-scale industrial manufacturing and commercialization of the Li-S batteries.

In order to eventually push for further industrial manufacturing and commercialization, we have spent years working on the Li-S chemistry for balanced solution. Here we’d like to share some results from our works on the Li-S system. A well-engineered carbon framework will be introduced and discussed for high sulfur loading electrodes fabrication. Corresponding critical parameters, as well as the performance evaluation of the obtained high loading electrode will be also discussed. The high loading of S on both material (> 75 wt%) and electrode level (> 70 wt %, > 3 mAh/cm2) enables a much improved electrochemical performance of the large size pouch format Li-S cell. A protected Li anode also helps improving Coulombic Efficiency and preventing shuttling effect. In addition, influence of polymer binder and electrolyte on the optimized electrodes will be discussed. Besides the cell performance, we’ll also share the principle on material screening, cell fabrication and cell design.