Societies’ increasing need for energy storage makes it necessary to explore new concepts beyond the traditional lithium ion battery. A promising candidate is the lithium-sulfur technology with the potential to increase the energy density of the battery by a factor of 3–5. However, so far the many problems with the lithium-sulfur system have not been solved satisfactory. Here we report on a new approach utilizing a self-standing reduced graphene oxide based aerogel directly as electrodes, i.e. without further processing and without the addition of binder or conducting agents. We can thereby disrupt the common paradigm of “no battery without binder” and can pave the way to a lithium-sulfur battery with a high practical energy density. The aerogels are synthesized via a one-pot method and consist of more than 2/3 sulfur, contained inside a porous few-layered reduced graphene oxide matrix. By combining the graphene-based aerogel cathode with an electrolyte and a lithium metal anode, we demonstrate a lithium-sulfur cell with high areal capacity (more than 3 mAh/cm2 after 75 cycles), excellent capacity retention over 200 cycles and good sulfur utilization. Based on this performance we estimate that the energy density of this concept-cell can significantly exceed the Department of Energy (DEO) 2020-target set for transport applications.
展开▼
机译：社会对能量存储的需求不断增长，因此有必要探索传统锂离子电池以外的新概念。锂硫技术是一个有前途的候选人，它有可能将电池的能量密度提高3-5倍。但是，到目前为止，锂硫系统的许多问题尚未得到令人满意的解决。在这里，我们报道了一种新方法，该方法利用自还原的基于氧化石墨烯的气凝胶直接作为电极，即无需进一步处理且无需添加粘合剂或导电剂。因此，我们可以打破“没有粘合剂就没有电池”的常见范式，并为实用能量密度高的锂硫电池铺平道路。气凝胶是通过一锅法合成的，由多于2/3的硫组成，包含在多孔的几层还原性氧化石墨烯基质中。通过将石墨烯基气凝胶阴极与电解质和锂金属阳极相结合，我们证明了锂硫电池具有较高的面容量（75个循环后大于3 mAh / cm 2 ），出色的容量保留超过200个循环，硫利用率高。基于此性能，我们估计此概念单元的能量密度可以大大超过能源部（DEO）2020年为运输应用设定的目标。
展开▼
