美国哈佛大学李鑫开发了固态锂金属电池的动态稳定性设计策略。相关研究成果于2021年5月12日发表于国际一流学术期刊《自然》。

固态电解液有望抑制锂（Li）枝晶的穿透，具有较高的机械强度1,2,3,4。然而，在实践中，实现电池用锂金属负极仍然具有挑战性，因为在电池组装或长时间循环过程中，陶瓷颗粒中经常会产生微米或亚微米大小的裂纹3,5。一旦裂纹形成，锂枝晶渗透是不可避免的。

该文中，研究人员描述了一种界面稳定性（对锂金属响应）分层结构的固态电池设计，实现无锂枝晶穿透的超高电流密度。多层设计将较不稳定的电解质夹在较稳定的固体电解质之间，通过在较不稳定的电解质层中局部分解，阻止了任何锂枝晶的生长。

研究人员提出了一种类似于膨胀螺旋效应的机制，即任何裂纹都由动态生成的分解填充，这些分解也受到很好的约束，可能是由分解引起的“锚定”效应。锂金属阳极与LiNi0.8Mn0.1Co0.1O2阴极的循环性能非常稳定，在20C倍率（8.6毫安/平方厘米）下循环10000次后容量保持率为82%，在1.5C倍率（0.64毫安/平方厘米）下循环2000次后容量保持率为81.3%。 在微米级正极材料水平上，该设计还实现了每千克110.6千瓦的比功率和每千克631.1瓦时的比能量。

附：英文原文

Title: A dynamic stability design strategy for lithium metal solid state batteries

Author: Luhan Ye, Xin Li

Issue&Volume: 2021-05-12

Abstract: A solid-state electrolyte is expected to suppress lithium (Li) dendrite penetration with high mechanical strength1,2,3,4. However, in practice it still remains challenging to realise a lithium metal anode for batteries, because micrometre- or submicrometre-sized cracks in ceramic pellets can frequently be generated during battery assembly or long-time cycling3,5. Once cracks form, lithium dendrite penetration is inevitable6,7. Here we describe a solid-state battery design with a hierarchy of interface stabilities (to lithium metal responses), to achieve an ultrahigh current density with no lithium dendrite penetration. Our multilayer design has the structure of a less-stable electrolyte sandwiched between more-stable solid electrolytes, which prevents any lithium dendrite growth through well localized decompositions in the less stable electrolyte layer. A mechanism analogous to the expansion screw effect is proposed, whereby any cracks are filled by dynamically generated decompositions that are also well constrained, probably by the ‘anchoring’ effect the decompositions induce. The cycling performance of the lithium metal anode paired with a LiNi0.8Mn0.1Co0.1O2 cathode is very stable, with an 82 per cent capacity retention after 10,000 cycles at a 20C rate (8.6 milliamps per centimetre squared) and 81.3 per cent capacity retention after 2,000 cycles at a 1.5C rate (0.64 milliamps per centimetre squared). Our design also enables a specific power of 110.6 kilowatts per kilogram and specific energy up to 631.1 watt hours per kilogram at the micrometre-sized cathode material level.

DOI: 10.1038/s41586-021-03486-3

Source: https://www.nature.com/articles/s41586-021-03486-3