Kapuria et al – Multipod Bi(Cu2-xS)n Nanocrystals formed by Dynamic Cation–Ligand Complexation and Their Use as Anodes for Potassium-Ion Batteries – Nano Letters, 2022, 22, 24, 10120-10127

Nilotpal Kapuria, Sumair Imtiaz, Abinaya Sankaran, Hugh Geaney, Tadhg Kennedy, Shalini Singh*, and Kevin M. Ryan*

Department of Chemical Sciences and Bernal Institute, University of Limerick, V94 T9PX Limerick, Ireland
Corresponding Authors: S. Singh (shalini.singh@ul.ie), K. M. Ryan (kevin.m.ryan@ul.ie)

Received: October 7, 2022 Revised: December 2, 2022 Published: December 6, 2022
Link to Paper: https://pubs.acs.org/doi/10.1021/acs.nanolett.2c03933

Abstract

We report the formation of an intermediate lamellar Cu−thiolate complex, and tuning its relative stability using alkyl phosphonic acids are crucial to enabling controlled hetero-nucleation to form Bi(Cu_2‑xS)_n heterostructures with a tunable number of Cu_2‑xS stems on a Bi core. The denticity of the phosphonic acid group, concentration, and chain length of alkyl phosphonic acids are critical factors determining the stability of the Cu−thiolate complex. Increasing the stability of the Cu−thiolate results in single Cu_2‑xS stem formation, and decreased stability of the Cu−thiolate complex increases the degree of hetero-nucleation to form multiple Cu_2‑xS stems on the Bi core. Spatially separated multiple Cu_2‑xS stems transform into a support network to hold a fragmented Bi core when used as an anode in a K-ion battery, leading to a more stable cycling performance showing a specific capacity of ~170 mAh/g after 200 cycles compared to ~111 mAh/g for Bi(Cu_2‑xS)_n single-stem heterostructures.
Keywords: Heterostructures, Metal/semiconductor, Potassium ion battery, Ligands, Intermediates, Catalyst-assisted, Seeded-growth