Boosting Lithium-Ion Transport Kinetics by Increasing the Local Lithium-Ion Concentration Gradient in Composite Anodes of Lithium-Ion Batteries

Abstract

Constructing composite electrodes is considered to be a feasible way to realize high-specific-capacity Li-ion batteries. The core–double-shell-structured Si@C@TiO2 would be an ideal design for such batteries, considering that carbon (C) can buffer the volume change and TiO2 can constrain the structural deformation of Si. Although the electrochemical performance of the shells themselves is relatively clear, the complexity of the multishell heterointerface always results in an ambiguous understanding about the influence of the heterointerface on the electrochemical properties of the core material. In this work, a multilayer film model that can simplify and simultaneously expand the area of the heterointerface is used to study the heterointerfacial behavior. First, a multilayer film TiO2/C with different numbers of TiO2/C heterointerfaces is studied. It shows that the electrochemical performance is enhanced apparently by increasing the number of TiO2/C heterointerfaces. On the one hand, the TiO2/C heterointerface exhibits a strong lithium-ion storage capacity. On the other hand, the TiO2/C heterointerface appears to effectively promote the local Li-ion concentration gradient and thus boost the Li-ion transport kinetics. Then, TiO2/C is combined with Si to construct a composite anode Si/C/TiO2. An obvious advantage of TiO2/C over single TiO2 and C is observed. The utilization rate of Si is greatly improved in the first cycle and reaches up to 98% in Si/C/TiO2. The results suggest that the electrochemical performance of Si can be greatly manipulated by the heterointerface between the multishells.

Regulating Lithium-Ion Transference Number of a Poly(vinyl alcohol)-Based Gel Electrolyte by the Incorporation of H3BO3 as an Anion Trapper

“…The charge curves could be divided into two regions. The bottom straight line region originated from the ohmic polarization caused by battery resistance that showed up instantaneously once the current was applied; the top curved line region was assigned to the concentration polarization formed by the Li + concentration gradient in the batteries . At each current density, the Li||Li battery using the B-PVA8 gel electrolyte shows a lower concentration polarization percentage, implying a more homogeneous distribution of Li + and larger t Li + in the B-PVA8 gel electrolyte than those in the PVA gel electrolyte.…”

Recent Advances in 2D Heterostructures as Advanced Electrode Materials for Potassium‐Ion Batteries

“…As known, there are many forms of carbon materials, such as graphite, graphene, hard carbon, and soft carbon materials. [69][70][71][72] Among them, graphite with a theoretical specific capacity of 279 mAh g À1 (corresponding to the formation of KC 8 ) and a low working voltage (<0.4 V vs. K/K þ ) has attracted considerable interest as PIB anode materials. [73,74] So far, some strategies have been developed to further improve the capacity of graphite for PIBs.…”

Facile Synthesis of Pre-Lithiated LiTiO2 Nanoparticles for Quick Charge and Long Lifespan Anode in Lithium-Ion Batteries

“…Nowadays, considerable attention has been focused on development of clean and renewable energy for electric vehicles and electronic devices and large-scale energy storage to replace fossil fuels. Lithium-ion batteries (LIBs) are considered to be one of the most suitable energy storage technologies for these applications owing to low toxicity and high energy density and power. − However, LIBs with the most successful commercial anodic material based on graphite (372 mA h g –1 ) cannot satisfy the rapidly rising market demands. − …”