Mapping out cracks and quantifying strain fields in Li-ion and Na-ion batteries with 3D-XRDCT

Alloyed anodes hold the key to unlocking higher capacity anodes for LIBs and SIBs with liquid electrolytes. This proposal seeks to implement microscale 3D-XRDCT to map cracking and quantify strains fields in Li-ion and Na-ion batteries (LIBs, SIBs) with high capacity alloy anodes such as Sn. Through this work, we will examine bulk and nanoporous-Sb particles in full capillary cells while being lithiated (and sodiated) in operando, to investigate the role that architecture plays in mechanically stabilizing high volume changes in alloy anodes to improve electrical conductivity and cycling performance. By comparing the bulk and nanoporous alloys, we aim to elucidate the role of structural stabilizers such as the NP-SbSn in preventing mechanical failure of the anode, and tie it to behaviour (capacity retention) at the cellular scale.

合金负极（alloyed anodes）是解锁搭载液态电解质（liquid electrolytes）的锂离子电池（Lithium-ion Batteries, LIBs）与钠离子电池（Sodium-ion Batteries, SIBs）高容量负极的核心关键。本研究拟采用微尺度三维X射线计算机断层扫描（microscale 3D-XRDCT），对搭载锡（Sn）等高容量合金负极的锂离子、钠离子电池开展开裂分布图谱绘制与应变场（strain fields）定量表征，通过此项工作，我们将在原位（operando）锂化与钠化过程中，对全毛细管电池（full capillary cells）内的块状锑颗粒与纳米多孔锑颗粒进行分析，以探究微观结构在调控合金负极大体积膨胀的机械稳定性、提升电导率与循环性能方面的作用机制，通过对比块状合金与纳米多孔合金的性能表现，我们旨在阐明NP-SbSn这类结构稳定剂（structural stabilizers）对负极机械失效（mechanical failure）的抑制作用，并将其与电芯尺度（cellular scale）下的容量保持率（capacity retention）表现建立关联。