High-performance all-solid-state batteries enabled by salt bonding to perovskite in poly(ethylene oxide)
High-performance all-solid-state batteries enabled by salt bonding to perovskite in poly(ethylene oxide)
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DOI：
10.1073/pnas.1907507116
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发表时间：
2019-08
期刊：
影响因子：
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通讯作者：
Henghui Xu;Po‐Hsiu Chien;Jianjian Shi;Yutao Li;Nan Wu;Yuanyue Liu;Yan‐Yan Hu;J. Goodenough
中科院分区：
文献类型：
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作者：
Henghui Xu;Po‐Hsiu Chien;Jianjian Shi;Yutao Li;Nan Wu;Yuanyue Liu;Yan‐Yan Hu;J. Goodenough
使用柔性固体聚合物电解质是获得在可接受的充电-放电循环速率下具有高存储电功率的全固态锂电池的常见策略。使用含有石榴石陶瓷的聚（环氧乙烷）的这种策略的商业实现是不成功的，并且枝晶在没有适当处理石榴石表面的情况下形成并生长穿过石榴石电解质。我们报道了使用钙钛矿Li+电解质代替石榴石陶瓷在25 °C下提供了足够的Li+电导率而没有枝晶形成。我们还证明了LiTFSI [锂双（三氟甲磺酰基）酰亚胺]盐的TFSI−阴离子与聚合物的结合，这增加了Li+电导率和Li+传输数。柔性和低成本的聚（环氧乙烷）（PEO）基电解质是有前途的全固态锂金属电池，因为它们与金属锂阳极的兼容性。然而，PEO固体电解质的低室温锂离子电导率和严重的锂枝晶生长限制了其在高能锂金属电池中的应用。在这里，我们制备了PEO/钙钛矿Li 3/8 Sr7/16 Ta 3/4 Zr 1/4 O3复合电解质，其在25和45 °C下的Li离子电导率分别为5.4 × 10−5和3.5 × 10−4 S cm−1; TFSI−（双三氟甲烷磺酰亚胺）的F−与钙钛矿表面Ta 5+之间的强相互作用改善了PEO/钙钛矿界面处的Li离子传输。对称的Li/复合电解质/Li电池在高达0.6 mA cm-2的高电流密度下显示出优异的循环性能。在金属锂阳极和复合电解质之间原位形成的固体电解质界面层抑制锂枝晶的形成和生长。全固态锂|LiFePO 4和高压Li|采用该复合电解质的LiNi0.8Mn0.1Co0.1O2电池具有库仑效率高、过电位小、循环稳定性好等优点。
Significance Use of a flexible solid polymer electrolyte is a common strategy to obtain an all-solid-state lithium battery of high stored electric power at acceptable charge–discharge cycling rates. Commercial realization of this strategy with poly(ethylene oxide) containing a garnet ceramic has been unsuccessful and dendrites form and grow across garnet electrolytes without proper treatment of the garnet surface. We report that use of a perovskite Li+ electrolyte in place of the garnet ceramic provides an adequate Li+ conductivity at 25 °C without dendrite formation. We also demonstrate a binding of the TFSI− anion of a LiTFSI [lithium bis(trifluoromethanesulfonyl)imide] salt to the polymer, which increases both the Li+ conductivity and the Li+ transport number. Flexible and low-cost poly(ethylene oxide) (PEO)-based electrolytes are promising for all-solid-state Li-metal batteries because of their compatibility with a metallic lithium anode. However, the low room-temperature Li-ion conductivity of PEO solid electrolytes and severe lithium-dendrite growth limit their application in high-energy Li-metal batteries. Here we prepared a PEO/perovskite Li3/8Sr7/16Ta3/4Zr1/4O3 composite electrolyte with a Li-ion conductivity of 5.4 × 10−5 and 3.5 × 10−4 S cm−1 at 25 and 45 °C, respectively; the strong interaction between the F− of TFSI− (bis-trifluoromethanesulfonimide) and the surface Ta5+ of the perovskite improves the Li-ion transport at the PEO/perovskite interface. A symmetric Li/composite electrolyte/Li cell shows an excellent cyclability at a high current density up to 0.6 mA cm−2. A solid electrolyte interphase layer formed in situ between the metallic lithium anode and the composite electrolyte suppresses lithium-dendrite formation and growth. All-solid-state Li|LiFePO4 and high-voltage Li|LiNi0.8Mn0.1Co0.1O2 batteries with the composite electrolyte have an impressive performance with high Coulombic efficiencies, small overpotentials, and good cycling stability.