銅銦複合材料應用於無陽極型鋰離子電池

Abstract

本研究針對無陽極鋰離子電池系統中鋰沉積行為之穩定性問題，揭示應用銅銦複合材料作為集流體之設計策略。經電化學電鍍法製備具不同銦含量與表面形貌之銅銦合金層，並結合對稱電池與無陽極全電池進行電化學測試與循環行為比較，以探討其對鋰金屬沉積/剝離反應之實質影響。實驗結果顯示，表面均勻且合金分布穩定之銅銦層可有效降低鋰沉積初期成核所需之過電位，顯著抑制枝晶生成並穩定鋰金屬/集流體界面，進而提升電池之循環壽命與能量效率。相較之下，表面粗糙或銦分布不均之樣品則於循環初期即表現出高過電位與容量不穩，曲線平台逐漸崩塌且放電容量快速衰退，顯示其界面結構難以支撐穩定反應。X射線光電子能譜分析進一步證實鋰沉積後In3d₅/₂與3d₃⁄₂主峰皆向低束縛能位移，並伴隨氧化態訊號消失，代表銦已與鋰形成合金化結構，有助於提供可逆吸脫鋰機制與穩定反應平台。此外搭配PEO@LiTFSI電解質系統引入EC作為添加劑進行導電性與鋰離子傳導數測試，結合鋰離子傳導數檢測可知其離子導電度提升之貢獻來自於鋰離子，惟其非隨EC摻雜比例增加而呈單調遞增，仍須輔以更多相關檢測說明之。本研究乃建立一套以銅銦合金為基礎之界面穩定化設計途徑，不僅可有效調控鋰沉積動力學與界面反應性，亦具潛力應用於全固態與高能量密度無陽極鋰金屬電池之長壽命模組設計中。

This study proposes a copper-indium composite as a current collector for stabilizing lithium metal deposition in anode-less lithium-ion batteries. Copper-indium alloy layers with varying compositions and surface morphologies were fabricated by electrochemical deposition, followed by symmetric and full-cell tests to investigate their effects on lithium plating/stripping behavior. Results indicate that samples with uniform alloy distribution and smooth surfaces exhibit lower overpotentials, suppress dendrite growth, and retain stable cycling performance.In contrast, samples with rough surfaces or uneven indium distribution show voltage instability and rapid capacity fading, indicating insufficient interfacial control. X-ray photoelectron spectroscopy confirms the formation of Li-In alloys after lithium deposition through binding energy shifts of In3d₅⁄₂ and In3d₃⁄₂ and the disappearance of oxide-related peaks, revealing a stable alloying mechanism for lithium accommodation.Additionally, by incorporating different ratios of EC into the PEO@LiTFSI electrolyte, ionic conductivity increased with EC content; however, Li⁺ transference numbers did not follow the same trend, highlighting the non-negligible contribution of TFSI⁻ anions to overall conductivity. Overall, the copper–indium design demonstrates the potential for interface engineering in anode-less lithium metal batteries and related solid-state systems.