SBIR Phase I: Improving Surface Properties of Stainless Steel for Li-ion Battery Current Collectors

这个小企业创新研究第一阶段项目旨在改善不锈钢在苛刻环境中的表面特性。特别是，它可能构成锂离子电池集流领域的重大改进。目前，在反复循环过程中，集流器金属会被腐蚀，导致容量下降，并出现与电池极化和过电位相关的潜在安全问题。该项目将把纳米材料和表面计量学的最新进展纳入一种性能显著提高的工程材料中。这个项目的智力优势在于对不锈钢进行了表面处理，进一步改变了氧化层的惰性、疏水性和耐腐蚀性。这种表面处理是通过在电抛光后对钢表面进行酸蚀来实现的，其方式类似于工业上重要的酸洗过程。所得到的钝化膜将被表征，原型表面处理部件将被评估为锂离子电池的集流器。这些集流器不仅可以提高耐腐蚀性（从而提高循环稳定性和电池安全性），而且还可以使用比目前更广泛的电解质。此外，该项目还可以应用于高性能不锈钢表面的其他应用。

This Small Business Innovation Research Phase I project intends to improve upon the surface characteristics of stainless steel in demanding environments. Particularly, it may constitute a significant improvement in the field of Li-ion battery current collectors. Today, current collector metal corrodes during repeated cycling leading to diminished capacity and potential safety issues related to cell polarization and over-potentials. This project will incorporate recent advances in nanomaterials and surface metrology into an engineering material with significant improvement in performance. The intellectual merit of this project lies in using a surface treatment to stainless steel that further modifies the oxide layer in terms of inertness, hydrophobicity, and corrosion resistance. This surface treatment is achieved by acid etching the steel surface after electropolishing in a manner similar to the industrially important pickling process. The resulting passive film will be characterized and prototype surface treated parts will be evaluated as current collectors for Li-ion batteries. These current collectors will not only improve corrosion resistance (and therefore cycling stability and cell safety), but will also allow use of a wider range of electrolytes than currently possible. Additionally, the project can lead to other applications where high performance stainless steel surfaces can be utilized.