TOWARD THE COMPLETE REMOVAL OF ORGANIC SOLVENTS

TOWARD THE COMPLETE REMOVAL OF ORGANIC SOLVENTS

Andrea Glawe R&D Director KROENERT GmbH& Co KG STATE OF THE ART The Coating Machinery Experts

Self-Metered CoatingTechniques Pre-Metered CoatingTechniques Self-Metered-Coating means that the applied coating weight depends on the process => e.g. Dip-Coating, Roller-Coating, Knife-Edge-Coating Pre-Metered-Coating means that the applied coating weight does NOT depend on the process => e.g. Slot-Die-Coating, Spray-Coating

Characterized by: - Capillary forces acting between slot-die and the substrate - Distances between slot die and substrate of less than 200µm The calculation of coating windows helps to control the process The following parameters are important - Fluid parameters (viscosity, surface tension) - Process parameters (distance between slot die and substrate, wet film thickness, substrate velocity) - Lip length of the slot-die m UW h B m Massflow B Coating Width h Wetfilm thickness Density

Slot die and web adjustment Angle adjustment +/- 5 Gap adjustment between slot die and substrate 0,5 µm steps Running precision coating roller 1 µm Precision of speed adjustment +/- 1 % Tension +/- 1 N Coating accuracy Coating weight variation +/- 1 % Coating thickness adjustment +/- 0,1 µm steps Coating accuracy from one to the other side +/- 0,1 mm Coating accuracy start and stop with intermitted coating +/- 0,6 mm Tolerance of the coating length +/- 0,5 mm Coating width +/- 0,1 mm

Intermitting Slot-Die Intermitting Comma-Coating Comma Slot-Die

How??? KROENERT development with partner TSE Troller Rotating bar-technique Valve-Technique

gravure coating / direct mode gravure coating / reverse mode backing roller (rubber) speed V br < V gr backing roller (rubber) speed V < V br gr web material web material gravure roller (steel) gravure geometry - different type gravure roller (steel) gravure geometry - different angle Lines per centimeter ratio Volume, ml/cm² depth, µm pyramidal hexagonal hexagonal Lines per centimeter ratio Volume, ml/cm² depth, µm trihelical lines PRINTING TECHNOLOGY G:/TBMBed/07-Bilder/Vorträge/Dr.Neumann G:/TBMBed/07-Bilder/Vorträge/Dr.Neumann Engravure for min 2 pt textures Hexagonal cell engraving All kinds of line-engraving Structures engraving Limitation with approx. 100 g/m² wet film thickness

Precise printing processes Compact pattern up to very fine and thin lines Register steering Layer 1 engraved roller printing Layer 2 screen printing

Jérôme Peyrard R&AE Project Manager RENAULT THE DEATH OF NMP

Benchmark Titanate based active material Capacity C/10 10 9 8 Irreversible capacity Industrial Market Synthesis - 7 6 5 4 3 2 1 Capacity 10C (power) Expected Durability Graphite TiO2B Li2TI3O7 solid state Material cost Li2TI3O7 fast solid state Li4Ti5O12 Selection of LTO material as Anode Active material for ELIBAMA project Develop and demonstrate an aqueous based cost efficient electrode manufacturing process.

Current collector Active material Aqueous binder conductor Aluminum LTO Solef 90000 Carbon

Electrochemical stability of the aqueous binder Compatibility LTO-Binder Current collector corrosion Main issue Studied solutions Electrochemical evalution on coin cells LTO Morphology (particles size, density,...) Mixing process ph adjustment Coating adhesion Binder selection (3 grades evaluated) Drying process (T ; ) Loading effect Current collector grades / treatments

Water based NMP based 3 steps: Lab, Pre-pilot, and Pilot scale

PILOT MIXING PILOT COATING CELLS WINDING 10 Ah CELLS

At Room Temperature cycling, after 400 cycles, less than 10% loss of capacity At 55ºC cycling, no capacity loss after 400 cycles.

LTO aq LTO NMP * Good adhesion for both LTO electrodes after 400 cycles * No delamination is observed * Few process default are showed Postmortem analysis shows similar aspect of LTO NMP and LTO aq electrodes even after 400 cycles at 55 C

o Fully NMP free anode manufacturing with high energy and cost savings. o Mechanical properties of LTO NMP and LTO aq electrode are similar (adhesion, results of post mortem analysis after 400 cycles at 55ºC, ) o No difference between new process (LTO- aqueous based) and organic process in terms of electrochemical performances (cycle life) especially no capacity loss after 400 cycles at 55ºC.

Julien Breger SAFT WHEN WATER REPLACES NMP

NMP is reprotoxic Flash point of NMP: 86-96 C REACH legal background : NMP was listed on the REACH Candidate List in June 2011. in March 2012 NMP was in the DRAFT 4 th recommendation from ECHA for inclusion on Annex XIV for Authorisation (=prioritization), with relatively high priority, but the major European Manufacturer of NMP, BASF, succeeded its lobbying with Netherlands and Netherlands submitted in June 2012 an intention to propose a restriction on NMP (Annex XVII) Indeed, restriction is both less costly and generally less risky for industry than Authorisation. Initial investment of solvent (NMP) recover system Work on water based cathode

Main issues addressed in the frame of ELIBAMA: Mixing Mixing Coating Coating Drying Drying Formulation: binder/thickener (nature, (nature, amount, amount, ) ) ) Aluminum Aluminum foil foil corrosion foil corrosion Ink Ink basicity Ink basicity for for particular for particular /+/ /+/ /+/ material material (Ni (Ni rich) (Ni rich) Requirement of of total of total water water removing removing Reactivity Reactivity of of /+/ /+/ of material /+/ material towards towards water: water: Possible Possible degradation of of of the the positive the positive material material PRESENTED TODAY

1 st step: Investigation on protecting additives at lab scale Assessment of different components (ph buffers, corrosion inhibitors, coated foils etc ) => choice of Additive A «Pearly» aspect: more severe corrosion Specific apparatus for these measurements

SEM analysis: Electrode Medium-range loadings SEM picture of Al foil after removing materials: No corrosion!!

Three trials were performed during the project, with constant improvement in terms of formulation optimisation etc.. 40Ah cylindrical cells were successfully produced (30 cells/series). Initial capacity and internal resistance now very close to reference!

Automotive-type cycling test (internal SAFT test) was performed Automotive-type Cycling test Capacity evolution Results are promising, but slightly less good than reference cells ELIBAMA Steering Committee Meeting M36 15 October 2014

Foil corrosion problem has been solved, thanks to a deep investigation at lab scale 40Ah cells were performed without any process issue (adhesion, calendering, filling etc..) with significant initial performances improvement all along the ELIBAMA project Comparable initial capacity/ir values to standard electrodes Cells are now under cycling and calendar life to check performances (initial performances are promising) Moisture level in electrode might need to be decreased even more (optimization of drying step)

Markus Cudazzo Fraunhofer IPA A NEW APPLICATION OF AN ELECTRODEPOSITION PROCESS

Mixing 2-3-component of electrochemically active function powder, powder binder and optional conductive agents are mixed with a well-defined sequence, defined environmental conditions and precisely adjusted process and cycle times No solvents and no water necessary Binder content comparable with liquid coating processes due to the improved mixing techniques and the use of a very fine powder binder Application The powder mixture is charged by direct contact of powder particles with a high-voltage electrode Advantage compared with common charging methods for powder coatings not suitable for (semi-)conductive powders: no ionic wind and reduced back spraying

Fast IR-treatment Before IR-treatment a pre-compacting of the layer has to take place to increase the thermal conductivity Depending from power density of the electrical Infrared just a few seconds exposure time necessary for powder melting Floor-space saving: compared with the drying of conventional liquid coatings carried out by a convection oven about factor 5-10 shorter area Calendering Required for a defined porosity and electrical conductivity, a sufficient adhesion on current collector as well as a good electrochemical activity of cathode To improve the adhesion most of the applications have been carried out on pre-coated samples (water based conductive precoat 5 µm dry film thickness)

Electrochemical activity Dry-blend coated samples of current collector foils show good results comparable with state-ofthe-art coatings Electron microscopic shot Functional Dry Blend coated layer for cathodes

Challenges for the future Improve the adhesion of functional layer by the use of improved powder binders and particle size distributions as well as improved mixing techniques New cell manufacturing process adjusted to the requirements of Dry Blend coatings Dry coating of Anode materials for lithium ion-batteries as well as other battery types and super caps Process integration focused on cell-manufacturing

Andrea Glawe R&D Director KROENERT GmbH& Co KG XXX

Simultaneous double side coating continuous as well as intermitted with highest precision Intermitted coating for cross stripes Slot die variation for length stripes Higher process speed up-to 100 m/min Wider working width up-to 1.600 mm Use of alternative drying and curing methods Thin-film batteries for small printed electronic devices (for instance printed sensor systems, label and protective smart clothing's)

An NMP free coating process will be a mandatory in a near future (cf regulation in Europe). Efficient NMP free coating processes may be a competitive advantage for European manufacturers. Aqueous based seems the most relevant candidate for a short term application. Solvent free alternatives give high opportunities to reduce the initial coating investment but need additional research activities to be transferred in mass production.

The ELIBAMA project is granted by the European Commission under the Nanosciences, nanotechnologies, materials & new production technologies (NMP) Theme of the 7th Framework Programme for Research and Technological Development.