Abstract Increasing energy and power densities is one of the important required improvements in lithium ion batteries. However, there exist limitations in increasing both energy and power densities simultaneously because of the increase in internal resistance. In this work, we report the simultaneous improvement of these properties of lithium ion battery by adopting a laser structured LiNi0.5Mn0.3Co0.2O2 cathode. The electrode was processed to make uniformly spaced micro-grooves by using a femtosecond laser. The performance of laser structured electrodes with varying thickness (100 ∼ 210 μm) and porosity (26% and 50%) were compared with that of unstructured conventional electrodes used in industry. It is demonstrated that the specific energy of thick and dense laser structured electrode (thickness = 175 μm, porosity = 26%) at 0.5C is about twice higher than that of thin and sparse unstructured electrode (thickness = 100 μm, porosity = 50%) while rate capability is almost the same. Also, although laser-structured electrodes are much thicker than unstructured electrodes, the rate performance (discharge capacity = 93%) of the laser-structured electrode is better than that of unstructured electrode at 1C. The simultaneous enhancement of the power and energy densities of the laser-structured electrodes results from the improvement of lithium ion diffusivity and cell polarization.

中文翻译：

---

激光成型低孔隙率厚电极提高锂离子电池性能

摘要 提高能量和功率密度是锂离子电池需要改进的重要内容之一。然而，由于内阻的增加，在同时增加能量和功率密度方面存在局限性。在这项工作中，我们报告了通过采用激光结构的 LiNi0.5Mn0.3Co0.2O2 阴极同时改善锂离子电池的这些性能。使用飞秒激光加工电极以形成均匀间隔的微槽。将具有不同厚度（100 ∼ 210 μm）和孔隙率（26% 和 50%）的激光结构化电极的性能与工业中使用的非结构化常规电极的性能进行了比较。结果表明，厚而致密的激光结构电极（厚度 = 175 μm，孔隙率 = 26%）在 0. 5C 比薄且稀疏的非结构化电极（厚度 = 100 μm，孔隙率 = 50%）高约两倍，而倍率性能几乎相同。此外，虽然激光结构电极比非结构化电极厚得多，但在 1C 时，激光结构化电极的倍率性能（放电容量 = 93%）优于非结构化电极。激光结构电极的功率和能量密度同时提高是由于锂离子扩散率和电池极化的改善。激光结构电极的倍率性能（放电容量 = 93%）在 1C 时优于非结构电极。激光结构电极的功率和能量密度同时提高是由于锂离子扩散率和电池极化的改善。激光结构电极的倍率性能（放电容量 = 93%）在 1C 时优于非结构电极。激光结构电极的功率和能量密度同时提高是由于锂离子扩散率和电池极化的改善。