Xiao Chuanlian, Wang Hongguang, Usiskin Robert, van Aken Peter A, Maier Joachim
Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany.
Science. 2024 Oct 25;386(6720):407-413. doi: 10.1126/science.adi5700. Epub 2024 Oct 24.
Insertion storage in battery electrodes and supercapacitive storage are typically considered to be independent phenomena and thus are dealt with in separate scientific communities. Using tailored experiments on titanium oxide thin films of various thicknesses, we demonstrate the simultaneous occurrence of both processes. For the interpretation of the entire storage profile encompassing both contributions, the (free) energies of the charge carriers in the mixed conductor and the neighboring phase are the only materials parameters required. The experimental results enable no less than a unification of insertion and supercapacitive storage, the first being dominant for thick films, the latter for thin films or negligible electronic conductivity. Therefore, the size of the storage medium and the nature of the current collecting phases can be used to tune power density versus energy density.
电池电极中的嵌入存储和超级电容存储通常被认为是独立的现象，因此在不同的科学领域中进行研究。通过对不同厚度的氧化钛薄膜进行定制实验，我们证明了这两种过程可以同时发生。对于包含两种贡献的整个存储曲线的解释，混合导体和相邻相中电荷载流子的（自由）能量是唯一所需的材料参数。实验结果实现了嵌入存储和超级电容存储的统一，厚膜中前者占主导，薄膜或电子电导率可忽略不计时后者占主导。因此，存储介质的尺寸和集流相的性质可用于调节功率密度与能量密度。
