Reversible Silicon Anodes with Long Cycles by Multifunctional Volumetric Buffer Layers

Abstract

Establishing a stable, stress-relieving configuration is imperative to achieve a reversible silicon anode for high energy density lithium-ion batteries. Herein, we propose a silicon composite anode (denoted as T-Si@C), which integrates free space and mixed carbon shells doped with rigid TiO 2 /Ti 5 Si 3 nanoparticles. In this configuration, the free space accommodates the silicon volume fluctuation during battery operation. The carbon shells with embedded TiO 2 /Ti 5 Si 3 nanoparticles maintain the structural stability of the anode while accelerating the lithium-ion diffusion kinetics and mitigating interfacial side reactions. Based on these advantages, T-Si@C anodes demonstrate an outstanding lithium storage performance with impressive long-term cycling reversibility and good rate capability. Additionally, T-Si@C//LiFePO 4 full cells show superior electrochemical reversibility. This work highlights the importance of rational structural manipulation of silicon anodes and affords fresh insights into achieving advanced silicon anodes with long life.

Adjustable Dimensionality of Microaggregates of Silicon in Hollow Carbon Nanospheres: An Efficient Pathway for High-Performance Lithium-Ion Batteries

“…In addition, the initial charge/discharge capacities of 0D, 1D, 2D, and 3D samples are 1311.9/2186.5, 2164.6/2705.7, 1925.5/2907.3, and 1709.0/2234.9 mAh g –1 with homologous initial Coulombic efficiencies (ICEs) of 60%, 80%, 66%, and 70%, respectively. For the first charge/discharge cycle, the irreversible capacity loss is due to building of an SEI film that is attributed to electrolyte reaction with electrode materials to form a passivation film with solid electrolyte property on a solid–liquid interface and electrolyte decomposition . Furthermore, the cyclic voltammetry (CV) curves of 0D–3D samples for the first three cycles at 0.2 mV s –1 are clarified to realize lithiation and delithiation reactions (Figure S12a–d).…”

“…For the first charge/discharge cycle, the irreversible capacity loss is due to building of an SEI film that is attributed to electrolyte reaction with electrode materials to form a passivation film with solid electrolyte property on a solid−liquid interface and electrolyte decomposition. 31 Furthermore, the cyclic voltammetry (CV) curves of 0D−3D samples for the first three cycles at 0.2 mV s −1 are clarified to realize lithiation and delithiation reactions (Figure S12a−d).…”

Unraveling the New Role of Metal–Organic Frameworks in Designing Silicon Hollow Nanocages for High-Energy Lithium-Ion Batteries

“…Note that average high capacities of 1506 mA h g –1 within 200 cycles at 0.5 A g –1 and 1009 mA h g –1 within 250 cycles at 1.0 A g –1 are superior to those performances of most Si-based anodes reported before (Table S1). ,,− …”

Porous, Encapsulated Si–O–C Lithium-Ion Battery Anode Materials from Silicone-Containing Polyesters: Influences of Graphene Oxides

“…The porous silicon materials provide free space for volume variation, and the hard outer layers can protect the SEI film from breakage. Silicon fibers or powders with this type of structure present long cycle, stable cyclability, and high specific capacity. , …”