Electrodeposited copolymer electrolyte into nanostructured titania electrodes for 3D Li-ion microbatteries

Abstract

The electrochemical synthesis of a copolymer electrolyte (PEO-PMMA) into titania nanotubes is described and studied. Compared with the electrochemical systems based on solid electrolytes deposited by top-down techniques, the copolymer/titania nanotube material reveals high electrochemical performance, opening new perspectives for the fabrication of 3D all-solid-state microbatteries.ß 2012 Published by Elsevier Masson SAS on behalf of Acade ´mie des sciences.

Highly conformal electrodeposition of copolymer electrolytes into titania nanotubes for 3D Li-ion batteries

“…For comparison, the CV curves recorded in monomer-free electrolyte are given in Figure 1b. It is important to note that the monomer is not electrochemically active, and the polymerization process is expected to be initiated by free hydrogen radicals produced at applied cathodic potentials higher than −1 V vs Hg/Hg 2 SO 4 , K 2 SO 4 (saturated) [13,20,25]. The similar shape of the CVs recorded in the two different electrolytes can be explained by the reactions involving the Ti 4+ /Ti 3+ and H + /H 2 redox couples.…”

“…However, when targeting 3D microbatteries, the conventional top-down approach to deposit solid electrolyte (e.g., lithium phosphorous oxynitride) [10-12] is not really suitable due to the accumulation of the electrolyte at the top of the nanotubes [13]. Certainly, with this accumulation of electrolyte, the 3D paradigm of microbatteries cannot be realized.…”

“…Indeed, electropolymerization is particularly powerful to control the deposition of different polymers into various porous materials [15-19]. Very recently, the use of electrodeposition to fill TiO 2 nt with a layer of poly(methyl methacrylate)-polyethylene oxide, i.e., PMMA-(PEO) 475 has been reported [13,20]. We have demonstrated that this simple bottom-up approach is adequate to deposit a homogeneous copolymer layer into titania nanotubes while improving the electrochemical performance.…”

Three‐Dimensional Self‐Supported Metal Oxides for Advanced Energy Storage

“…Key to the successful fabrication of a full 3D microbattery is the conformal deposition of electrolyte on the 3D self‐supported electrode material to preserve the 3D architecture. Initial attempts at depositing LiPON by sputtering resulted in a LiPON layer which tended to cover the top of the nanotubes (see Figure a) though very little was found in the voids within and between the nanotubes . Consequently, an electropolymerization technique was developed for the conformal coating of the anodized TiO 2 NTs .…”

Self‐Organised TiO2 Nanotubes for 2D or 3D Li‐Ion Microbatteries

“…Djenizian and co‐workers have studied the lithium storage behaviour of self‐organised TiO 2 nanotubes coated with a layer of room‐temperature Li + ‐conducting gel‐type PEO‐PMMA copolymer (see Figure 33 a–d) 39b. 149b, 156 Nacimiento et al 157. have shown that improvements in the lithium storage behaviour of self‐organised TiO 2 nanotubes can be obtained by coating the nanotubes with Li + ‐conducting polyacrylonitrile through the use of electropolymerisation.…”