B-doped SiO_(x) composite with three dimensional conductive network for high performance lithium-ion battery anode

Currently,the practical application of SiO_(x) still has a huge hindrance in the area of lithium ion battery,because it is unable to achieve an effective contact with surrounding conducting materials,resulting in failure to form lithium ion migration tunnels.In this work,we presented a facile method to synthesize the B-doped SiOx composite by adhering SiO_(x) particles with MWCNT(multi-walled carbon nanotube)under the assistance of lithium metaborate(LiBO_(2)).LiBO_(2),as a sintering aid,not only can react with SiO_(x) to form a compacted framework,but also build a three-dimensional(3D)conductive network for ions transportation.Furthermore,B-SiO_(x)@CNT@LBO anode delivers a remarkable lithium storage performance in terms of long cycles and high rate capability.A full cell coupled with NCM622 cathode achieves a high energy density of 429.5 Wh kg^(-1) based on the total mass of cathode.

Solid and Liquid Metastable Phase Equilibria in the Aqueous Quaternary System Li＋, Mg2＋//SO42-, Borate-H2O at 273.15 K

The metastable phase equilibria of the Li＋, Mg2＋//SO42-, borate-H2O system at 273.15 K were studied using isothermal evaporation method. The dry-salt phase diagram, water-phase diagram and the physicochemical property diagrams of the system were plotted with the metastable solubility values and physicochemical properties corresponding to density, refractive index, pH value and conductivity. The dry-salt diagram was composed of four crys- tallizing zones[lithium sulfate hydrate（Li2SO4·H2O）, epsomite（MgSO4·7H2O）, lithium metaborate octahy- drate（LiBO2.8H2O）, and hungchaoite（MgB4O7·9H2O）], five univariant curves and two invariant points （Li2SO4·H2O＋MgSO4·7H2O＋MgB4O7·9H2O and Li2SO4·H2O＋LiBO2-8H2O＋MgB4O7·9H20）. Li2B4O7 converted in- to LiBO2 in solution. Comparing the metastable phase diagram at 273.15 K and stable phase diagram at 298.15 K for the system, the crystallized area of Li2SO4·H2O and MgSO4·7H2O became large, whereas, the other phase regions became small. The J（H2O） changes regularly with increasing J（SO42-）, and the physicochemical properties change regularly with the concentration of B4O72- increasing.