Unification of insertion and supercapacitive storage concepts: Storage profiles in titania

• 成果类型: Article
• 署名作者: Xiao, Chuanlian; Wang, Hongguang; Usiskin, Robert; van Aken, Peter A.; Maier, Joachim
• 署名单位: Max Planck Society; Honeywell
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12197
• DOI: 10.1126/science.adi5700
• 发表日期: 2024-10-25
• 页码: 407-413
• 关键词: electrochemical energy-storage; atomic layer deposition; metal fluorides; li-storage; thin-films; lithium; electrolytes; tio2; conduction; hydrogen

摘要

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.