Electrodeposition of porous Si film from SiO2 in molten BaCl2-CaCl2-NaCl

Template‐Free Electrochemical Formation of Silicon Nanotubes from Silica

“…[43] Constant-voltage electrolysis is conducted, with the cell voltage between the solid cathodes and graphite anode being at 2.2-2.6 V to avoid the formation of Ca-based alloys. [31][32][33][34][35][36][37][38][39][40][41] The cathode potential (versus Ag/AgCl) was monitored in one case during constant-voltage electrolysis at a cell voltage of 2.2 V ( Figure S1, Supporting Information), which shows that the cathode potential (versus Ag/AgCl) during the two-electrode-electrolysis process is consistent with that in the CV curves in Figure 2a, further verifying the preferential reduction of AgCl and formation of Ag-Si.…”

“…[31][32][33][34][35][36][37][38][39][40][41] However, the solid-solid conversion from SiO 2 to Si makes the nucleation-growth process of Si hardly tunable, therefore construction of hollow Si nanostructure by molten salt electrolysis of silica is an insurmountable challenge. [31][32][33][34][35][36][37][38][39][40][41] As for coating a conductive buffer layer on the surface of Si nanostructures, carbon is commonly used as the candidate. [12][13][14][15][16] However, the unpleasant SiC is readily generated during molten salt electrolysis, therefore making the in situ coating strategy far from expectations.…”

“…The electrode kinetics for molten salt electrolysis of solid silica for Si extraction is governed by ohmic polarization and mass transfer of/through the solid cathode. [31][32][33][34][35][36][37][38][39][40][41] Electrolysis of SiO 2 -AgCl for Si formation ranks among the highest performance in terms of current efficiency (74%, Figure 4m) and energy consumption (12.1 kW h kg Si −1 , Figure 4m). This energyconsumption value is even lower than that of industrial production of metallurgical-grade silicon (>20 kW h kg Si −1 ), [41] promising future industrial production of Si nanotubes.…”

Toward Cost‐Effective Manufacturing of Silicon Solar Cells: Electrodeposition of High‐Quality Si Films in a CaCl2‐based Molten Salt

“…[13] However,f ew reports on electrodeposition of high quality and photoactive Si films in CaCl 2 -based molten salts can be found in the literature. [14] Here,w ed emonstrate the successful deposition of dense Si films with high purity onto graphite from molten CaCl 2 -CaO-SiO 2 at 1123 K. Thef ilm exhibits good photoelectrochemical properties and clear PV effects.W ebelieve that this study has laid the foundation for an ew process to manufacture Si solar cells via molten salt electrochemical techniques.…”

Toward Cost‐Effective Manufacturing of Silicon Solar Cells: Electrodeposition of High‐Quality Si Films in a CaCl2‐based Molten Salt

“…systematically investigated the electrochemical reduction behaviors of solid SiO 2 in molten CaCl 2 and proposed a new production process for solar Si feedstock . However, few reports on electrodeposition of high quality and photoactive Si films in CaCl 2 ‐based molten salts can be found in the literature …”