Polymer‐Templated Formation of Polydopamine‐Coated SnO₂ Nanocrystals: Anodes for Cyclable Lithium‐Ion Batteries

Abstract

Well-controlled nanostructures and a high fraction of Sn/Li O interface are critical to enhance the coulombic efficiency and cyclic performance of SnO -based electrodes for lithium-ion batteries (LIBs). Polydopamine (PDA)-coated SnO nanocrystals, composed of hundreds of PDA-coated "corn-like" SnO nanoparticles (diameter ca. 5 nm) decorated along a "cob", addressed the irreversibility issue of SnO -based electrodes. The PDA-coated SnO were crafted by capitalizing on rationally designed bottlebrush-like hydroxypropyl cellulose-graft-poly (acrylic acid) (HPC-g-PAA) as a template and was coated with PDA to construct a passivating solid-electrolyte interphase (SEI) layer. In combination, the corn-like nanostructure and the protective PDA coating contributed to a PDA-coated SnO electrode with excellent rate capability, superior long-term stability over 300 cycles, and high Sn→SnO reversibility.

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

“…Additionally, the lithium ions cannot be totally extracted from these materials without instigating the structural collapse of the cathode; this restriction leads to even lower obtainable capacities (e.g., LiCoO 2 (≈140 mAh g −1 ) and LiFe 2 O 4 (≈130 mAh g −1 )) . Therefore, researchers have turned to alternative anode materials with features of high capacity, good cycling stability, appropriate working voltage, high electronic/ionic conductivity, and low cost to remarkably increase the energy density, lifespan, safety, fast charging/discharging capability, and affordability of next‐generation LIBs …”

“…The TC of SnO 2 (1494 mAh g −1 ) is lower than Si (4199 mAh g −1 ) and Ge (1624 mAh g −1 ), but much higher than Sn (993 mAh g −1 ) and TMOs (≈700–1000 mAh g −1 ). In contrast to Si, Ge, and Sn, one of the most considerable advantages of SnO 2 is its capability to be facilely fabricated, which can be achieved using one‐step hydrothermal or solvothermal processes at relatively low temperatures . However, Si, Ge, and Sn are normally synthesized via complex or high‐cost methods such as the reductive decomposition of Si precursor in the presence of reductants (e.g., hydrogen, magnesium, carbon, etc.)…”

“…The Sn coarsening‐induced volume shrinkage of reversible reaction region (i.e., SnO 2 or Li 4.4 Sn layer at the Sn/Li 2 O interface in Figure 2c) is the main reason for the capacity decay of SnO 2 . Thus, preparing nanosized SnO 2 materials with robust structures that repeatedly generate small Sn NPs during the cycling process has been identified as a feasible method to improve the conversion and alloying reaction reversibility of SnO 2 and achieve high capacity anode materials …”

Schwefel‐basierte Elektroden mit Mehrelektronenreaktionen für Raumtemperatur‐Natriumionenspeicherung

“…[3] Praktisch einsetzbare Na-Ionen-Batterien haben bisher allerdings nicht mehr als eine relativ niedrige Energiedichte von ca. [13] Die Kapazitäten dieser Materialien beruhen auf Mehrelektronenreaktionen und erreichen 400-950 mA hg À1 . [2b, 4] Wissenschaftler sind daher bestrebt, diese Schwelle zu überwinden.…”

Capillary-Induced Ge Uniformly Distributed in N-Doped Carbon Nanotubes with Enhanced Li-Storage Performance

“…Many strategies have been developed to synthesize 1D structured materials, such as the hydrothermal, chemical‐vapor deposition, electrospinning, and chemical polymerization methods. Another method is to use a carbon matrix, which could accommodate volume changes, enhance electrical conductivity of the electrode, and serve as an active material for lithium storage . In particular, nanoparticles encapsulated in carbon nanotubes represent the most desirable structure, which could not only benefit from the advantages of 1D structure, but also provide void spaces to buffer the volume changes of active materials .…”