Veeraraghavan Vijay D, Frenck Louise, Maslyn Jacqueline A, Loo Whitney S, Parkinson Dilworth Y, Balsara Nitash P
Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States.
ACS Appl Mater Interfaces. 2021 Jun 16;13(23):27006-27018. doi: 10.1021/acsami.1c04582. Epub 2021 Jun 7.
Growing demand for rechargeable batteries with higher energy densities has motivated research focused on enabling the lithium metal anode. A prominent failure mechanism in such batteries is short circuiting due to the uncontrolled propagation of lithium protrusions that often have a dendritic morphology. In this paper, the electrodeposition of metallic lithium through a rigid polystyrene--poly(ethylene oxide) (PS--PEO or SEO) block copolymer electrolyte was studied using hard X-ray microtomography. In this system, protrusions were approximately ellipsoidal globules: we take advantage of this simple geometry to quantify their growth as a function of polarization time and electrolyte salt concentration. The growth of 47 different globules was tracked with time to obtain average velocities of globule growth into the electrolyte. The globule diameter was a linear function of globule height in the electrolyte with a slope of about 6, independent of time and electrolyte salt concentration.
对具有更高能量密度的可充电电池不断增长的需求推动了旨在实现锂金属阳极的研究。此类电池中一个突出的失效机制是由于锂突出物不受控制的生长（通常具有树枝状形态）导致的短路。在本文中，使用硬X射线显微断层扫描技术研究了通过刚性聚苯乙烯 - 聚（环氧乙烷）（PS - PEO或SEO）嵌段共聚物电解质进行金属锂的电沉积。在该系统中，突出物近似为椭球形小球：我们利用这种简单的几何形状来量化它们作为极化时间和电解质盐浓度函数的生长情况。跟踪了47个不同小球随时间的生长情况，以获得小球在电解质中生长的平均速度。小球直径是电解质中小球高度的线性函数，斜率约为6，与时间和电解质盐浓度无关。
