Work

Porous Structuring of Si Microparticles for Li-Ion Battery Anodes by Urea-Assisted Etching

Year: 2026

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Silicon-based anodes offer substantially higher theoretical capacities than graphite in lithium-ion batteries, but their practical deployment is hindered by severe volume changes that induce mechanical degradation and unstable interfacial chemistry. While nanoscaling strategies can mitigate these effects, they often suffer from low tapped density, complex synthesis, and limited scalability. Porous silicon microparticles provide a promising alternative by partially accommodating volume expansion while preserving processability and electrode-level integrity. Here, a HF-free urea-assisted etching strategy is employed to generate porous silicon microparticles under mild conditions, leveraging the coupled action of thermally induced structural disruption and chemically driven surface modification. Control experiments confirm that the combined action of these effects is essential to achieve BJH-resolved mesoporosity and increased surface area. The resulting porous silicon exhibits oxygen- and nitrogen-containing surface functionalities. Composite electrodes prepared with nanographite and sodium alginate binder at graphite:silicon:binder ratios of 8:1:1, 7:2:1, and 4.5:4.5:1 demonstrate improved electrochemical behavior. In half-cell testing, electrodes containing 10–20 wt % porous silicon deliver stable redox activity and retain 630–880 mAh g –1 after 100 cycles at 0.1 C, with Coulombic efficiencies of 98.8–99.7%, whereas higher silicon loadings lead to rapid capacity decay. Cycling-resolved impedance and differential-capacity analyses reveal the formation of a thicker yet mechanically resilient interphase that stabilizes charge-transfer kinetics, while rate capability tests show 65–74% capacity retention at 2 C.

Source: ACS Omega

DOI: 10.1021/acsomega.5c12477

Authors: Ali Abo-Hamad, Manisha Phadatare, Daniel Brandell, Maria Hahlin, Jonas Örtegren

Institutions: Mid Sweden University, Uppsala University

Language: English

Topic: Advancements in Battery Materials

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $1,935