High-Performance All-Solid-State Lithium-Sulfur Battery Enabled by a Mixed-Conductive Li2S Nanocomposite
High-Performance All-Solid-State Lithium-Sulfur Battery Enabled by a Mixed-Conductive Li2S Nanocomposite
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DOI：
10.1021/acs.nanolett.6b01754
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发表时间：
2016-07-01
期刊：
影响因子：
10.8
通讯作者：
Wang, Chunsheng
中科院分区：
文献类型：
--
作者：
Han, Fudong;Yue, Jie;Wang, Chunsheng
使用高导电性硫化物基固体电解质的全固态锂硫电池（ASSLSB）由于电极的巨大体积变化以及S和Li 2S的差的电子和离子导电性而遭受低硫利用率、差的循环寿命和低倍率性能。缓解这些挑战的最有前途的方法在于制造由均匀分布的纳米活性材料、固体电解质和碳组成的硫纳米复合材料电极。在这里，我们报道了一种新的自下而上的方法来合成这样的纳米复合材料，通过溶解Li 2S作为活性材料，聚乙烯吡咯烷酮（PVP）作为碳前体，和Li 6PS 5Cl作为固体电解质在乙醇中，然后通过共沉淀和高温碳化过程。Li 2S活性材料和Li 6PS 5Cl固体电解质具有类似于4 nm的颗粒尺寸被均匀地限制在纳米级碳基质中。由具有锂储存能力、机械增强以及离子和电子导电性的不同性质的不同纳米颗粒组成的均匀纳米复合材料电极使得ASSLSB的机械稳健和混合导电（离子和电子导电）硫电极成为可能。在室温下，即使在Li 2S的高负载量（类似于3.6mg/cm（2））下，也实现了在50 mA/g下60次循环的830 mAh/g（71%的Li 2S利用率）的大可逆容量，具有高倍率性能。这项工作提供了一种新的策略，设计一个机械鲁棒性，混合导电纳米复合电极的高性能全固态锂硫电池。
All-solid-state lithium-sulfur batteries (ASSLSBs) using highly conductive sulfide-based solid electrolytes suffer from low sulfur utilization, poor cycle life, and low rate performance due to the huge volume change of the electrode and the poor electronic and ionic conductivities of S and Li2S. The most promising approach to mitigate these challenges lies in the fabrication of a sulfur nanocomposite electrode consisting of a homogeneous distribution of nanosized active material, solid electrolyte, and carbon. Here, we reported a novel bottom-up method to synthesize such a nanocomposite by dissolving Li2S as the active material, polyvinylpyrrolidone (PVP) as the carbon precursor, and Li6PS5Cl as the solid electrolyte in ethanol, followed by a coprecipitation and high-temperature carbonization process. Li2S active material and Li6PS5Cl solid electrolyte with a particle size of similar to 4 nm were uniformly confined in a nanoscale carbon matrix. The homogeneous nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic and electronic conductivities enabled a mechanical robust and mixed conductive (ionic and electronic conductive) sulfur electrode for ASSLSB. A large reversible capacity of 830 mAh/g (71% utilization of Li2S) at SO mA/g for 60 cycles with a high rate performance was achieved at room temperature even at a high loading of Li2S (similar to 3.6 mg/cm(2)). This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance all-solid-state lithium sulfur batteries.