Domino Reactions Enabling Sulfur-Mediated Gradient Interphases for High-Energy Lithium Batteries.

Silicon (Si)-based anodes are currently considered a feasible solution to improve the energy density of lithium-ion batteries owing to their sufficient specific capacity and natural abundance. However, Si-based anodes exhibit low electric conductivities and large volume changes during cycling, which could easily trigger continuous breakdown/reparation of the as-formed solid-electrolyte-interphase (SEI) layer, seriously hampering their practical application in current battery technology. To control the chemoelectrochemical instability of the conventional SEI layer, we herein propose the introduction of elemental sulfur into nonaqueous electrolytes, aiming to build a sulfur-mediated gradient interphase (SMGI) layer on Si-based anodes.

Electrolysis Process-Facilitated Engineering of Primary Particles of Cobalt-Free LiNiO for Improved Electrochemical Performance.

The particle morphology of LiNiO (LNO), the final product of Co-free high-Ni layered oxide cathode materials, must be engineered to prevent the degradation of electrochemical performance caused by the H2-H3 phase transition. Introducing a small amount of dopant oxides (NbO as an example) during the electrolysis synthesis of the Ni(OH) precursor facilitates the engineering of the primary particles of LNO, which is quick, simple, and inexpensive. In addition to the low concentration of Nb that entered the lattice structure, a combination of advanced characterizations indicates that the obtained LNO cathode material contains a high concentration of Nb in the primary particle boundaries in the form of lithium niobium oxide.

Electrolyzed Ni(OH) Precursor Sintered with LiOH/LiNiO Mixed Salt for Structurally and Electrochemically Stable Cobalt-Free LiNiO Cathode Materials.

Cobalt-free LiNiO cathode materials offer a higher energy density at a lower cost than high Co-containing cathode materials. However, Ni(OH) precursors for LiNiO cathodes are traditionally prepared by the coprecipitation method, which is expensive, complex, and time-consuming. Herein, we report a fast, facile, and inexpensive electrolysis process to prepare a Ni(OH) precursor, which was mixed with LiOH/LiNO salts to obtain a LiNiO cathode material.