Decoding the Role of Trace Impurities: Systematic Study of Unintentional Dopants on CE Using Ultra-Pure and Deliberately Doped Systems

Even tiny amounts of “dirt” or leftover chemicals in batteries might help or hurt lithium efficiency—let’s test pure materials versus ones with controlled impurities to see if any “happy accidents” can be engineered on purpose.

Research Question: How do trace impurities—either from raw materials or processing steps—impact Coulombic Efficiency, and can beneficial effects be intentionally harnessed for battery optimization?

Hypothesis: Certain trace elements or compounds, often considered contaminants, may catalyze favorable SEI formation or lithium kinetics, and their controlled introduction could improve CE.

Experiment Plan: Prepare ultra-pure silicon and lithium metal anodes, and systematically introduce controlled ppm-level dopants (e.g., Mg, B, F, or others guided by incidental findings in Lin et al., 2024 and others). Measure ICE and cycling CE, SEI composition, and electrode morphology. Use advanced characterization (e.g., ToF-SIMS, XPS) to correlate impurity type/concentration with CE and SEI structure. Aim to identify impurity types that reliably boost CE, offering a new “doping” strategy for battery manufacturing.

References:

• Lin, Z., Sun, P., Zhou, C., & Fang, Z. (2024). Low-Cost Silicon from Natural Sand with Tunable Oxygen Content and Its Effects on the Electrochemical Properties of Lithium-Ion Battery Anodes. ACS Omega.