внедрение лития

The reversible insertion of lithium into electrodes based on amorphous boron has been studied. The reversible capacity upon the lithium insertion has been found to be about 750 mA⋅h/g. The most efficient in terms of specific capacity are the electrodes containing graphene as a conductive additive.

Thin-film amorphous silicon electrodes, subjected to various pretreatment have been tested in galvanostatic and potenciodynamic modes. Preliminary heat treatment of silicon electrodes in nitrogen atmosphere was established to lead to some decrease in discharge capacity and insignificant decrease in degradation upon cycling. Preliminary annealing of silicon electrodes in vacuum at 480°C results in increase of discharge capacity and some decrease of degradation upon cycling. Silicon electrodes with thickness about 1 micron annealed in vacuum have discharge capacity about 1200 mA·h/g.

Silicon electrodes with regular porous structure were prepared by the photoelectrochemical etching of single-crystal n-type silicon wafers, followed by the removal of the substrate. Electrodes with pores having circular and square section were studied. The porosity was increased via additional oxidation with the subsequent etching of oxide. The electrochemical characteristics of anodes were found to depend on porosity, electrodes with porosity 60-70% possessing maximal capacity for lithium reversible insertion. Electrodes thus prepared feature much higher capacity per area unit (up to 25 mA·h/cm2) than usual thin-film electrodes (about 1 mA·h/cm2).