AtMoS 2 pheric SuperGen Meeting - Imperial 2016 Early Career - - PowerPoint PPT Presentation

AtMoS2pheric SuperGen Meeting - Imperial 2016 Early Career Research Fellowship

Dr Marcus Jahn (on behalf of Dr M. J. Loveridge) Warwick University

AtMoS2pheric

AtMoS2pheric –The Challenge

Background

In LIBs with conventional electrode structures, after 100s of charge- discharge cycles, physical degradation is a dominant failure mode

Courtesy of website of Energy and Power Group at University of Oxford, http://epg.eng.ox.ac.uk/content/degradation-lithium-ion-batteries (accessed Feb. 12, 2015).

Why MoS2?

Divergence of uses for this material…….

…..extending to…….

Why MoS2?

The Energy Storage Quadrilemma

S = 10th most abundant element Stable trigonal prismatic phase 670mAh/g capacity Li or Na-ion possibilities Environmentally benign energy storage

Co-Materials

Graphene n-Cellulose Graphene to enhance conductive network and capacity Cellulose to augment tensile properties and improve structural integrity of hierarchical interactions

Graphene Morphology

Cu foil FL-graphene/PAA 15µm BET S.A. = 123m2/g

DFT Pore size distribution

Graphene E-Chem

FLG stacked in layers of variable numbers → capacity developing over a range of potentials

→ Sloping V profile in Cycle 1

>500mAh/g vs. Li for >40 cycles but poor CE and large FCL%

MoS2 Hydrothermal Synthesis

UCL CHFS material

CHFS rapidly mixes supercritical water & cold aqueous solutions of metal salts. ↓ Supersaturated solution, particles rapidly crystallize and react with a narrow PSD. ↓ Chemical reagents may be added to the metal salt to control the size, shape, aspect ratio and functional properties of nanoparticles produced.

Scalable Process

Awarded DLS Beamtime for Feb 2017

EE14764 "Investigating Graphene-enhanced MoS2 Nano-Ribbon Anodes for High Capacity Li and Na-ion Batteries using Combined Synchrotron Operando X-Ray Diffraction and XAS."

6 shifts I15

There is still considerable debate surrounding the structural intermediates formed during lithiation. I15 with accelerating V up to 60kV needed to penetrate electrode and cell

Project Plan

WP ACTIVITY LEA Comm START DURATION PERIODS (Weeks) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

1 Literature Review 1 10 2 Non-Optimised Benchmark with MoS2 8 10 2.1 Materials Procurement 8 4 2.2 Small Scale Ink Mixing 12 2 2.3 Determine Coating Parameters 12 2 2.4 Coin Cell Testing 14 5 3 Novel MoS2 Nanoribbons 18 8 3.1 Synthesis by UCL 18 6 3.2 Incorporation into non-optimised mix 19 4 3.3 Mechanical Testing of electrode films 19 2 3.4 Ink optmisation 22 3 3.4.1 Binary binder systems 22 3 3.4.2 Cross-linking post processing procedures 22 3 3.5 Coin Cell Testing 23 5 4 Electrolyte Additives 25 4 4.1 Screening of Additives 25 3 4.2 Coin Cell Testing 26 4 5 Electrode Additives 30 8 5.1 Ink formulation 30 4 5.2 Coin Cell Testing 34 4 6 Scale Up formulation and Process Optimisation 39 12 6.1 Identification of best ink 39 1 6.2 Mixing/Coating parameter optimisation 39 4 6.3 Large batch coating and pouch assembly 45 4 6.4 Pouch cell testing 47 8 6.5 Post-Mortem analysis 49 5 6.6 Diamond Light Source and data analysis 45 2 7 Dissemination 50 4 7.1 Final Project Report 50 4 7.2 Preparation of publications 50 4

Target Performance

MoS2 in Li-Ion MoS2 in Na-Ion

1245 | ACS Appl. Mater. Interfaces 2013, 5, 1240−1247 429 | Electrochimica Acta 2013, 92, 427– 432

First Development Trials vs. Li

• MoS2 (SigmaAldrich, <2µm)

84.5 wt.%

• CMC (Targray, C30000A)

10.9 wt.%

• C65 (Imerys)

4.6 wt.%

• Solid content

10%

• Li counter electrode
• →600 mAh/g specific capacity targeted
• First coin cells on test