Linking Solid Electrolyte Degradation to Charge Carrier Transport in the Thiophosphate-Based Composite Cathode toward Solid-State Lithium-Sulfur Batteries
Linking Solid Electrolyte Degradation to Charge Carrier Transport in the Thiophosphate-Based Composite Cathode toward Solid-State Lithium-Sulfur Batteries
复制标题
固体电解质降解与硫代磷酸盐复合阴极中载流子传输的关系
DOI：
10.1002/adfm.202010620
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发表时间：
2021-02-24
影响因子：
19
通讯作者：
Zeier, Wolfgang G.
中科院分区：
文献类型：
--
作者：
Ohno, Saneyuki;Rosenbach, Carolin;Zeier, Wolfgang G.
固态锂硫电池（SSLSB）有可能导致能量存储的范式转变。新兴的高导电固体电解质的使用实现了高能量和功率密度。然而，需要电解质和导电添加剂的紧密混合物来补偿阴极活性材料S-8和Li 2S的绝缘性质引起强烈的电解质降解。因此，更好地理解阴极组分之间具有极高界面密度的阴极复合材料的电化学和传输性质是至关重要的。在这里，通过利用球磨的复合材料的锂argyrodite Li 6PS 5Cl和碳作为模型电极，在复合材料中的稳定性，可逆性和运输作为阴极负载的函数，导电相的体积分数，温度，和施加的电位进行了全面的调查。通过比较电解质降解的起始电位和通过传输线模型分析确定的复合材料的有效离子电导率的急剧下降，通过在可达到的容量和有效载流子传输之间的平衡证明了SSLSB的容量保持率的成功增强，在室温下100次循环后实现了3.68 mAh cm（-2）的高面积容量。这里观察到的分析适用于具有电绝缘活性材料的任何固态复合材料。
Solid-state lithium-sulfur batteries (SSLSBs) have the potential to cause a paradigm shift in energy storage. The use of emerging highly-conductive solid electrolytes enables high energy and power densities. However, the need for an intimate mixture of electrolyte and conductive additives to compensate for the insulating nature of cathode active materials S-8 and Li2S induces intense electrolyte degradation. Thus, it is paramount to understand better the electrochemical and transport properties of the cathode composite with extremely high interface density among cathode components. Here, by utilizing a ball-milled composite of the lithium argyrodite Li6PS5Cl and carbon as a model electrode, the stability, reversibility, and transport in the composite as functions of cathode loading, the volume fraction of conducting phase, temperature, and applied potentials are comprehensively investigated. Comparing the onset potentials of electrolyte degradation and the sharp drop in the effective ionic conductivity of the composite determined through transmission-line model analysis, successful enhancement of the capacity retention of SSLSBs is demonstrated by balancing between the attainable capacity and effective carrier transport, achieving a high areal capacity of 3.68 mAh cm(-2) after 100 cycles at room temperature. The here-observed analysis is applicable to any solid-state composite with electrically insulating active materials.