In situ surface protection for enhancing stability and performance of conversion-type cathodes
In situ surface protection for enhancing stability and performance of conversion-type cathodes
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DOI：
10.1557/mre.2017.11
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发表时间：
2017-08
影响因子：
4.3
通讯作者：
Feixiang Wu;O. Borodin;G. Yushin
中科院分区：
文献类型：
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作者：
Feixiang Wu;O. Borodin;G. Yushin
在转化阴极上使用原位形成的保护层被引入作为一种廉价且简单的策略，以保护这些材料免受与液体电解质的不期望的相互作用。转换型阴极已被视为取代下一代锂（Li）和锂离子电池的基于Ni和Co的嵌入型阴极的有希望的候选者，其具有更高的比能量、更低的成本和潜在的更长的循环寿命。通常，在转化反应中，每一个硫族元素原子可以存储两个或三个Li离子（例如，S或Se）或过渡金属（例如，用于卤化物中的Fe或Cu）。不幸的是，在转化化学中，活性材料或中间充电/放电产物在有机电解质中遭受各种不利的相互作用和溶解。在这篇小型评论文章中，我们讨论了当前的界面挑战，并重点关注阴极表面原位形成的保护层，以有效地保护转换材料免受与液体电解质的不良相互作用。我们进一步探讨了形成这种保护层的机制和目前的进展，通过使用各种盐，溶剂和添加剂，以及从分子模拟的洞察力。最后，我们讨论了未来的机会和前景，在原位表面保护。
The use of in situ formed protective layer on conversion cathodes was introduced as a cheap and simple strategy to shield these materials from undesirable interactions with liquid electrolytes. Conversion-type cathodes have been viewed as promising candidates to replace Ni- and Co-based intercalation-type cathodes for next-generation lithium (Li) and Li-ion batteries with higher specific energy, lower cost, and potentially longer cycle life. Typically, in conversion reactions two or three Li ions may be stored per just one atom of chalcogen (e.g., S or Se) or transition metal (e.g., Fe or Cu used in halides). Unfortunately, in conversion chemistries the active materials or intermediate charge/discharge products suffer from various unfavorable interactions and dissolution in organic electrolytes. In this mini-review article, we discuss the current interfacial challenges and focus on the protective layers in situ formed on the cathode surface to effectively shield conversion materials from undesirable interactions with liquid electrolytes. We further explore the mechanisms and current progress of forming such protective layers by using various salts, solvents, and additives together with the insight from molecular modeling. Finally, we discuss future opportunities and perspectives of in situ surface protection.