SnO2 as Advanced Anode of Alkali‐Ion Batteries: Inhibiting Sn Coarsening by Crafting Robust Physical Barriers, Void Boundaries, and Heterophase Interfaces for Superior Electrochemical Reaction Reversibility

• Published in: Advanced energy materials Vol. 10; no. 6
• Main Authors: Zhao, Shiqiang, Sewell, Christopher D., Liu, Ruiping, Jia, Songru, Wang, Zewei, He, Yanjie, Yuan, Kunjie, Jin, Huile, Wang, Shun, Liu, Xueqin, Lin, Zhiqun
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.02.2020
• Subjects: alkali‐ion batteries; Anodes; Barriers; Boundaries; Carbonaceous materials; Conducting polymers; Electrode materials; Electrodes; Failure mechanisms; Flux density; heterophase interface; Inorganic materials; Lithium; Metal oxides; Metal sulfides; Nanoparticles; physical barrier; Storage batteries; Storage capacity; Structural hierarchy; Tin dioxide; tin dioxide (SnO2); void boundary
• DOI: 10.1002/aenm.201902657
• ISSN: 1614-6832

Superior reaction reversibility of electrode materials is urgently pursued for improving the energy density and lifespan of batteries. Tin dioxide (SnO2) is a promising anode material for alkali‐ion batteries, having a high theoretical lithium storage capacity of 1494 mAh g− based on the reactions of SnO2 + 4Li+ + 4e− ↔ Sn + 2Li2O and Sn + 4.4Li+ + 4.4e− ↔ Li4.4Sn. The coarsening of Sn nanoparticles into large particles induced reaction reversibility degradation has been demonstrated as the essential failure mechanism of SnO2 electrodes. Here, three key strategies for inhibiting Sn coarsening to enhance the reaction reversibility of SnO2 are presented. First, encapsulating SnO2 nanoparticles in physical barriers of carbonaceous materials, conductive polymers or inorganic materials can robustly prevent Sn coarsening among the wrapped SnO2 nanoparticles. Second, constructing hierarchical, porous or hollow structured SnO2 particles with stable void boundaries can hinder Sn coarsening between the void‐divided SnO2 subunits. Third, fabricating SnO2‐based heterogeneous composites consisting of metals, metal oxides or metal sulfides can introduce abundant heterophase interfaces in cycled electrodes that impede Sn coarsening among the isolated SnO2 crystalline domains. Finally, a perspective on the future prospect of the structural/compositional designs of SnO2 as anode of alkali‐ion batteries is highlighted. Three key strategies for inhibiting Sn coarsening to enhance the reaction reversibility of SnO2 as anodes of alkali‐ion batteries are presented, i.e., homogenously encapsulating SnO2 nanoparticles in robust physical barriers, constructing hierarchical/porous/hollow‐structured SnO2 architectures with stable void boundaries, and fabricating SnO2‐based heterogenous composites for introducing abundant heterophase interfaces.