Waterborne Polyurethane Used as Binders for Lithium-Ion Battery with Improved Electrochemical Properties

Abstract

LiFePO4based Lithium-ion batteries are prepared by nonionic waterborne polyurethane with different soft segments which act as binder. FTIR is used to characterize the structure of waterborne polyurethanes .The emulsion viscosity, mechanical properties of films are measured. The result shows that, the emulsion viscosity and tensile strength of polyurethane based polyether glycol are smaller than polyurethane based polyester. Charge-discharge, cycle performance and AC impedance spectroscopy measurement indicat that the first charge-discharge efficiency is 92%, the biggest discharge capacity is 115 mAh/g for lithium-ion batteries based on waterborne polyurethane as adhesive which equaled to PVDF, the batteries have a good cycle performance and high cycle efficiency and the impedance of batteries are small than PVDF.

Polyurethane Binder for Aqueous Processing of Li-Ion Battery Electrodes

“…This step is necessary to reduce electrode porosity, increase electrical conductivity (due to better contact of active material and conductive agent particles) and enhance adhesion to the current collector. 30 However, anode electrodes do not suffer of poor electronic conductivity and adhesion, thus, they were not calendered in this study to avoid damages of the graphite active material. 31 Table II.…”

“…While the authors researched the impact of different polyurethane binder formulations on the volume change during charge and discharge of only graphite anodes, however, no electrochemical data was reported. Very recently Zhu et al 30 investigated self-synthesized nonionic waterborne polyurethane as binder for cathode electrodes, utilizing lithium iron phosphate (LFP) as active material.To shed more light on the opportunities of polyurethanes as binder in aqueous-processed Li-ion batteries, we examined the electrochemical stability of a one component heat-curable polyurethane dispersion, the influence of different polyurethane concentrations on the performance of anode and cathode electrodes and their electrochemical properties in a Li-ion battery. CMC was used in small percentages as electrode thickener to maintain a favorable viscosity of the electrode slurries.…”

“…While the authors researched the impact of different polyurethane binder formulations on the volume change during charge and discharge of only graphite anodes, however, no electrochemical data was reported. Very recently Zhu et al 30 investigated self-synthesized nonionic waterborne polyurethane as binder for cathode electrodes, utilizing lithium iron phosphate (LFP) as active material.…”

Silicone-urethane membranes for lithium batteries. Part 1. Moisture-cured poly(siloxane-urethane-urea) elastomers containing polyethylene oxide (PEO) segments - synthesis and characterization as potential membrane materials

“…Solid polymer separators designed for lithium batteries are usually based on copolymers containing polyethylene oxide (PEO) segments because it is well known that conductivity in such systems is facilitated by complexation of lithium ions (Li + ) by oxyethylene units. [7] Thus, the use of polyurethanes containing PEO segments as gel-type or solid electrolyte membrane materials in lithium batteries was reported in a number of papers, [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] and it was suggested [26] that in such membranes, lithium ions can form coordination complexes not only with PEO segments but also with urethane moieties, so ionic conductivity could be further enhanced. Silicone polymers and copolymers, especially containing PEO pendant segments, were also proposed as polymer matrices in lithium batteries [28][29][30][31][32] because it was anticipated that the loose packing of polysiloxane (SIL) chains, which is a well-known feature of silicones, would increase mobility of lithium ions in the polymer matrix.…”

Developments in aqueous polyurethane and polyurethane-acrylic dispersion technology. Part II. Polyurethane-acrylic dispersions and modification of polyurethane and polyurethane-acrylic dispersions

“…-binders for inks [117]; -binders for ceramic powders [118][119][120][121][122][123]; -semi-permeation membranes [124,125]; -single-ion electrolytes in batteries [126][127][128]; -paper sizing agents [129,130]; -retanning agents for collagen fibres (APUD containing pendant fluorescent groups in a polymer chain) [131].…”