Built-in Electric Field-Assisted Surface-Amorphized Nanocrystals for High-Rate Lithium-Ion Battery

Abstract

High-power batteries require fast charge/discharge rates and high capacity besides safe operation. TiO2 has been investigated as a safer alternative candidate to the current graphite or incoming silicon anodes due to higher redox potentials in effectively preventing lithium deposition. However, its charge/discharge rates are reluctant to improve due to poor ion diffusion coefficients, and its capacity fades quickly with rate as only thinner surface layers can be effectively used in faster charge/discharge processes. Here, we demonstrate that surface-amorphized TiO2 nanocrystals greatly improve lithium-ion rechargeable battery performance: 20 times rate and 340% capacity improvement over crystalline TiO2 nanocrystals. This improvement is benefited from the built-in electric field within the nanocrystals that induces much lower lithium-ion diffusion resistance and facilitates its transport in both insertion and extraction processes. This concept thus offers an innovative and general approach toward designing battery materials with better performance.

Surface‐Amorphous and Oxygen‐Deficient Li3VO4−δ as a Promising Anode Material for Lithium‐Ion Batteries

“…All the results would improve the reaction kinetics and achieve the performance enhancements of Li 3 VO 4− δ . The similar results have already been reported for various TiO 2− x nanocrystals as an anode material 32, 33, 34. Chen and co‐workers attributed this phenomenon to the “built‐in electric field” across the interface between the amorphous layer and the crystalline core 33.…”

Eco-friendly synthesis of rutile TiO2 nanostructures with controlled morphology for efficient lithium-ion batteries

“…[13][14][15] However, the poor electronic conductivity and low lithium ion diffusion coefficient of TiO 2 materials still hinder their further applications in energy storage. [16][17][18] To overcome these problems and further improve the electrochemical performance of TiO 2 materials, one available method is to rationally construct the 4 hybrids by modifying TiO 2 with metals, metal oxides and carbon materials. [19][20][21][22] In general, the construction of TiO 2 composites needs a relatively complicated process, thus resulting in a high-cost.…”

Hydrogenated Anatase: Strong Photocatalytic Dihydrogen Evolution without the Use of a Co‐Catalyst

“…[6,18,19] In contrast, Chen and Mao ascribed their finding to the formation of an amorphous layer at the outermost part of their TiO2 nanoparticles. [12,[20][21][22] In literature, thus, overall, for various reductive approaches, visible light absorption in TiO2 nanoparticles and a considerable number of effects is observed, independent of the exact nature of the treatment.…”