Alloy-Type Lithium Anode Prepared by Laser Microcladding and Dealloying for Improved Cycling/Rate Performance

Abstract

Nanosized alloy-type materials (Si, Ge, Sn, etc.) present superior electrochemical performance in rechargeable batteries. However, they fail to guarantee cycling capacity and stability under high mass loading required by industrial applications due to low electric contact and adhesive strength, which has long been a challenge. This work proposes a rational design for an alloy-type anode via facile and versatile laser microcladding and dealloying. The proposed anode features a large-area porous network composed of continuous nano-ligaments, which consist of evenly distributed nanosized alloy-type material metallurgically bonded with conductive material. The fabrication of the structure is validated using Ge–Cu and Sn–Cu anodes, both exhibiting enhanced cycling stability at high areal capacity and rate performance in lithium-ion batteries. The enhancement is attributed to the structural features, which contribute to lithiation–delithiation stability and intact electron/Li ion transference path, as verified by in situ and ex situ transmission electron microscopy observations. More importantly, the critical solidification conditions of laser microcladding are provided by a multiphysics simulation, allowing for a thorough understanding of the structural formation mechanism. The study provides a possible approach to improve mass loading and performance of an alloy-type anode for practical application.

Characteristic Activity Parameters of Electron Donors and Electron Acceptors

“…Electron transfer (ET) reaction (eq ) is the most basic chemical reaction and exists widely in nature. Since the electron transfer process plays the core role in material metabolism, energy conversion, photosynthesis, biosynthesis and transformation, and many other processes, scientists in many fields such as physics, chemistry, biology, power source, and so on have all paid much more attention to the issues on the electron transfer process. − Among the many important issues on the electron transfer process, one of the most core issues is how to quantitatively predict the activation free energy Δ G ≠ (XE/Y) of electron transfer reactions (eq ). Although quite a lot of empirical and theoretical equations have been proposed by some scientists such as London–Eyring–Polanyi–Sato (LEPS), − Johnston and Parr, , Marcus, , Murdoch, Rehm and Weller, Agmon and Levine, Bell, le Noble, Lewis, , Kurz, Thornton, Zavitsas, , and Ahrland–Chatt–Davies–Williams to quantitatively predict the activation free energy of electron transfer reactions in terms of some parameters of electron transfer reactions, none can be used to quantitatively estimate the activation free energy of electron transfer reactions based on only one characteristic parameter of electron donors and one characteristic parameter of electron acceptors as the calculation of the thermodynamic driving forces Δ G 0 (XE/Y) of electron transfer reactions (eq ), which can be calculated based on only one characteristic parameter of electron donors and one characteristic parameter of electron acceptors (i.e., the oxidation potential of electron donors and the reduction potential of electron acceptors).…”

Rational Design and Engineering of 1D Heterostructured Porous Sn/CoSnx@C Nanotubes for Superior Lithium Storage

“…23 However, the introduction of the intractable nonreactive metallic M phase reduces the specific capacity of the cell, which is a major problem for Sn-based alloys/intermetallic compound cathodes. 24 Therefore, regulating the ratio and composition of the inactive metals and Sn remains a critical challenge to improving the capacity and cycle performance of Sn-based anodes.…”

“…relative to Li is an effective strategy to relieve volume inflation, − in which the inactive metal in the formed Sn-based alloy is conducive to relieve the mechanical stress caused by the volume dilatation in the lithiation/delithiation process and improve the cyclic performance. , Besides, the N-doped carbon can provide a conductive pathway for the diffusion of Li + and prevent particle agglomeration and efficiently reduce the shrinkage/expansion effect during cycling. − By simultaneously introducing an inactive metallic Co matrix and N-doped carbon nanotubes into the hollow CoSn nanocrystals, the CoSn@N–C nanotubes exhibit high reversible capacities . However, the introduction of the intractable nonreactive metallic M phase reduces the specific capacity of the cell, which is a major problem for Sn-based alloys/intermetallic compound cathodes . Therefore, regulating the ratio and composition of the inactive metals and Sn remains a critical challenge to improving the capacity and cycle performance of Sn-based anodes.…”

Stress Mitigation of Nanosilicon Anode to Achieve Energy‐Dense and Highly‐Stable Full Cell

“…[1,2] However, lattice change results in huge volume expansion (>300%), which induces severe stress and deformation to pulverize Si structure, thus attenuating the cycling life of LIBs. [3] Numerous studies have verified that expansion stress can be relieved by reducing Si dimension to the nanoscale. [4] Cycling performance has been improved owing to the use of nano-Si with a stably expanded structure.…”