Work

Li Insertion in Ball Milled Si-Mn Alloys

Year: 2018

Type: article

Abstract: Si 1- x Mn x (0 ≤ x ≤ 0.5, Δ x = 0.05) alloys were prepared by ball milling and studied as negative electrode materials in Li cells. These alloys were found to be unique among transition metals. When x ≤ 0.35, the alloys are essentially homogeneous with nanocrystallites of Si 19 Mn 11 uniformly dispersed in a matrix of amorphous silicon. Nanocrystallites of SiMn and Si 19 Mn 11 coexist in samples with x > 0.35. The formation of Li 15 Si 4 during lithiation was totally suppressed for alloys with x ≥ 0.3. Cycling performance was significantly improved by Mn addition, especially for the samples in which the formation of Li 15 Si 4 was suppressed. The addition of Mn increases the particle size, which results in reduced surface area. Capacity trends suggest that inactive Si 19 Mn 11 and SiMn phases were formed in these alloys, consistent with XRD results. The x = 0.25 alloy achieved a volumetric capacity of 1526 Ah/L with 95% capacity retention after 50 cycles.

Source: Journal of The Electrochemical Society

DOI: 10.1149/2.0381809jes

Authors: Yidan Cao, J. Craig Bennett, R. A. Dunlap, M. N. Obrovac

Institutions: Dalhousie University, Acadia University, Clean Technologies Research Institute

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: hybrid

Estimated APC paid: $1,950