Template Synthesis of Polypyrrole‐Coated Spinel LiMn2 O 4 Nanotubules and Their Properties as Cathode Active Materials for Lithium Batteries

Abstract

Thbules of 200 nm outer diameter spinel LiMn3O4 were prepared by thermal decomposition of an aqueous solution containing lithium nitrate and manganese nitrate at 1:2 molar ratio using a nanoporous alumina membrane as a template. After dissolving the template membrane, the resulting nanotubule array of LiMn2O4 was coated with polypyrrole to investigate the galvanostatic charge-discharge characteristics. The polypyrrole-coated LiMn2O4 tubule electrodes exhibited higher capacities than the polypyrrole-coated LiMn2O4 thin-film electrode prepared under the same conditions, except for the use of the alumina membrane; it was ca. 2.5 times greater at 0.1 mA cm2 and became ca. 12 times greater with an increase in current density to 1.0 mA cm* The observed high capacity of the tubule electrode seems to have resulted from two kinds of effects: a decrease in real current density of high specific surface area at the tubule electrode and a decrease in thickness of LiMn2O4 solid phase for Li ions to diffuse through during the charging and discharging reactions.

Increasing the Affinity Between Carbon-Coated LiFePO4/C Electrodes and Conventional Organic Electrolyte by Spontaneous Grafting of a Benzene-Trifluoromethylsulfonimide Moiety

“…[9][10] In order to limit the undesired effects of surface reactions and enhance the conductivity of the cathode material, numerous studies reported surface modification of cathode material for lithium-ion batteries. [11][12][13][14][15][16][17][18][19][20][21] Organic and inorganic coatings that were investigated include electroactive polymers such as (thiophene, poly (3,4-ethylenedioxythiophene), 11 polypyrrole 12 and polyaniline 13 ), as well as metal oxides (MgO, 14 TiO 2 , 15 SiO 2 16 and ZrO 2 17 ). Ammonium polyacrylic acid dispersant 18 and surfactants like polyetheramine, 19 poly(ethyleneimine) 20 or anionic Avanel S-150 21 were used to promote better electrolyte wettability of the particle surface.…”

Sulphur–TiO2 yolk–shell nanoarchitecture with internal void space for long-cycle lithium–sulphur batteries

“…T here has been a steady increase in the demand for highperformance and long-lasting rechargeable batteries for a wide range of applications, ranging from portable electronics and consumer devices to electric vehicles and large-scale grid energy storage [1][2][3][4][5][6][7][8][9] . Unfortunately, the energy density and cycle life of existing lithium-ion batteries remain insufficient for many of the aforementioned applications, prompting the urgent need for new electrode materials with much higher charge capacities [1][2][3][4][5] .…”

High-power lithium ion microbatteries from interdigitated three-dimensional bicontinuous nanoporous electrodes

“…It is challenging to integrate 3D electrodes into a complete microbattery cell, owing to the difficulty of integrating 3D elements of anode and cathode materials, along with the need to control materials uniformity and feature sizes across a range of length scales of 10 nm-1 mm. A number of 3D half-cell electrode designs for microbatteries, consisting of only the anode or cathode, have been presented 10,13,[19][20][21][22][23] . There are, however, only a few publications reporting the performance of microbattery cells having fully integrated 3D anodes and cathodes [13][14][15][16] .…”