New materials for electrochemical storage

- from post Li-ion to post Li systems

Maximilian Fichtner, Helen Maria-Joseph, Mario Ruben, Ping Gao, Zhirong Zhao-Karger

AABC Mainz, 2017

2AABC Mainz | 31.. January 2017

Content

Motivation

The polysulfide issue in Li-S cells and a potential solution

Secondary Mg sulfur cells

Organic cathodes

Summary

3AABC Mainz | 31.. January 2017

Motivation for post Li-ion and post Li

Sustainability

• elemental abundance

• recyclability

• ecological footprint

• toxicity

Better Batteries

• cost

• energy density

• power

• safety

4AABC Mainz | 31.. January 2017

Evolutionary versus revolutionary materials

Gravimetric energy density (Wh/kg)

Li-ion

Ca/CoF3

Chlorides

Mg/CuCl2

Ca/CuCl2

Li/CuCl2

Fluorides

La/CoF3

Ca/CoF3

Li/FeF3

Li/CuF2

Selected battery

concepts

▪ Lithium ion

batteries

▪ Metal sulphur

batteries

▪ Metal oxygen

batteries

▪ Novel battery

chemistries

▪ Liquid metal

batteries

LiC6 / NMC

Vo

lum

etr

ice

ne

rgy

de

nsity

(Wh

/l)

Mg

batteries

Metal

Sulphur

Li/S

Mg/S

Metal-

Air

Li/O2

Mg/O2

Zn/O2Na/O2

Cathode:

Li-S BatteryThe polysulfide problem

5AABC Mainz | 31.. January 2017

Formation of polysulfides in lithium-sulfur batteries

Polysulfides are

intermediates

in the transition of

S8 to S2-

- gradual dissolution of

cathode

- Self-discharge

- Different voltage

plateaus

Y.-S. Su et al., Nature (2013)

6AABC Mainz | 31.. January 2017

smaller S22-

would not

dissolve !

Approach to eliminate formation of soluble polysulphides

Ultramicroporous carbon

made from coconut shells

(inexpensive, scalable).

Pore ø 0.6 nm

S8 and soluble S82-

do not fit in pore

Hypothesis:

direct transition of S to Li2S2 and Li2S

one reaction step one plateau

50 mass% S loading

e-

e-

Li+

No entering of

electrolyte into

the pore

S. Xin et al, JACS (2012).

7AABC Mainz | 31.. January 2017

Single Plateau !

Separator after 10 and 400 cycles is

not colored and thus shows

no indication of polysulfide

(also not detectable by UV-vis in

electrolyte)

No polysulfide formation

M. Helen, M. Fichtner et al.,

Scientific Reports (2015)

8AABC Mainz | 31.. January 2017

XPS from subsurface sulfur (S 2p)

As prepared sample (A) shows neutral sulfur

(red, 163.9 and 165.1 eV).

During discharge, the electrodes analyzed

along the length of the plateau (Position B, C

and D) exhibits only a single intermediate

polysulphide (blue) that converted to Li2S

(green) at the end of the discharge (E).

M. Helen, M. Fichtner et al., Scientific Reports

5 (2015) 12146

163.9 eV Neutral Sulphur

162.2 eV Li2S2

160.9 eV Li2S

re-charged

9AABC Mainz | 31.. January 2017

Evolutionary versus revolutionary materials

Gravimetric energy density (Wh/kg)

Li-ion

Ca/CoF3

Chlorides

Mg/CuCl2

Ca/CuCl2

Li/CuCl2

Fluorides

La/CoF3

Ca/CoF3

Li/FeF3

Li/CuF2

Selected battery

concepts

▪ Lithium ion

batteries

▪ Metal sulphur

batteries

▪ Metal oxygen

batteries

▪ Novel battery

chemistries

▪ Liquid metal

batteries

LiC6 / NMC

Vo

lum

etr

ice

ne

rgy

de

nsity

(Wh

/l)

Mg

batteries

Metal

Sulphur

Li/S

Mg/S

Metal-

Air

Li/O2

Mg/O2

Zn/O2Na/O2

Cathode and anode:

Mg sulfur batteries

10AABC Mainz | 31.. January 2017

First

Electrolytes,

Grignard-based

Electrolytes:

Lewis acid-base complexes

Mg2Cl3+ [A]-

nucleophilic !

Electrolytes:

Lewis acid-base complexes

Mg2Cl3+ [A]-

non-nucleophilic !

Electrolytes:

Mg-salts with big anions

Mg2+ [A]-

non-nucleophilic

Cl-free

Gregory, 1988

2000

2011

2016

Electrolyte development is key

Sulfur can be easily reduced

and needs non-nucleophilic

electrolyte

11AABC Mainz | 31.. January 2017

Single crystal XRD

½ [Mg2Cl3][(HMDS)AlCl3] + 3/2 (HMDS)AlCl2

(HMDS)2Mg + 2AlCl3

ORTEP plot of

[Mg2(µ-Cl)3·6THF] [HMDS·AlCl3]·THF

(H atoms are omitted for clarity)

Mg2(μ-Cl)3·6THF]+·THF [HMDS AlCl3]-

Mg dichloro-complex

glymes, THF, IL, DME,….

Features

• non-nucleophilic

• versatility w. solvents

• up to 2 M Mg2+ solutions

• 99% electrolyte efficiency

• stability up to 3.9 V

• used in-situ

Zh. Zhao-Karger, M. Fichtner, et al. RSC Adv. (2013)

Zh. Zhao-Karger, M. Fichtner, et al., Adv. Energy Mater. (2015)

12AABC Mainz | 31.. January 2017

A. Manthiram et al., ACS Energy Lett. (2016)

Zh. Zhao-Karger, M. Fichtner, et al.,

Adv. Energy Mater. (2015)

Mg2(μ-Cl)3·6THF]+·THF [HMDS AlCl3]-

Improvement by engineering, e.g. of separator

13AABC Mainz | 31.. January 2017

A novel Cl-free electrolyte

Mg[L] / DEG-TEG

• Mg [L] with big anion, easy to synthesize

• Cl-free salt

• soluble in ethers

• non-nucleophilic

• 3.8 V stability limit

• > 98% efficiency

Zh. Zhao-Karger, M. Fichtner (2017) EP Application; paper in preparation

uncoated separator

14AABC Mainz | 31.. January 2017

Major issues to be solved

• Kinetic barriers / overpotentials are still too high

• Role of surface layers on Mg?

• Reversibility

• Fate of the sulfur in the system

15AABC Mainz | 31.. January 2017

Evolutionary versus revolutionary materials

Gravimetric energy density (Wh/kg)

Li-ion

Ca/CoF3

Chlorides

Mg/CuCl2

Ca/CuCl2

Li/CuCl2

Fluorides

La/CoF3

Ca/CoF3

Li/FeF3

Li/CuF2

Selected battery

concepts

▪ Lithium ion

batteries

▪ Metal sulphur

batteries

▪ Metal oxygen

batteries

▪ Novel battery

chemistries

▪ Liquid metal

batteries

LiC6 / NMC

Vo

lum

etr

ice

ne

rgy

de

nsity

(Wh

/l)

Mg

batteries

Metal

Sulphur

Li/S

Mg/S

Metal-

Air

Li/O2

Mg/O2

Zn/O2Na/O2

Organic electrodes

16AABC Mainz | 31.. January 2017

Organic electrodes

▪ Good theoretical capacity

▪ Structural diversity and flexibility

▪ Tunable properties

▪ Good safety

▪ Low cost

▪ Easy processing

▪ Sustainability and environmental

friendliness

▪ Broad field of applications:

o Li, Na and Mg based batteries

o supercapacitors

o redox flow batteries

o all-organic batteries

Z. Song & H. Zhou, Energy Environ. Sci., 2013, 6, 2280.

17AABC Mainz | 31.. January 2017

A new class of highly conjugated porphyrin complex enabling high performance of rechargeable batteries

Porphyrins

N

N N

N

N

NH N

HN

SiSi

N

NH N

HN

BrBr

Si

5%mol Pd(PPh3)4, 5%mol CuI

THF/Et3N

2

yield 52%

yield 80%

THF/CH2Cl2

N

N N

N

SiSi

Cu(OAc)2.2H2O

THF/Et3N

TBAFCuCu

yield 95%

3

1 4

Hemocyanin-derived

(Molluscs, Arthropoda)

4 electron transfer from 16 to 20 𝜋 electrons; OCV vs. Li: 3.0 V

RR

18AABC Mainz | 31.. January 2017

Structure: self-assembly of porphyrin

Single crystal data

cation-π-stacking (staircase structure)

P.Gao, M. Fichtner et al., submitted (2017)

3.2 Å interlayer distance

19AABC Mainz | 31.. January 2017

Irreversible feature in 1st cycle

as-prepared electrode after initial cycle

P.Gao, M. Fichtner et al., submitted (2017)

Bedioui, F. et al., Acc. Chem. Res. (1995)

Electropolymerization

IR data

20AABC Mainz | 31.. January 2017

Working principle

Rechargeable batteries based on porphyrin

CuDEPP

Theoret. capacity: 187 mA h g-1 (four electrons)

Porphyrin works as both electron donor and acceptor

Cu2+ center does not participate

21AABC Mainz | 31.. January 2017

Rate performance and cycling

Cell: Li / LiPF6 / CuDEPP

22AABC Mainz | 31.. January 2017

Ragone Plot

Power density

measured up to 30

kW/kg

Cell 1: Li/LiPF6/CuDEPP (as cathode)

Cell 2: CuDEPP/PP14TFSI/Graphite (as anode)

P. Gao, Z. Zhao-Karger, M. Fichtner et al.,

WO Application and paper submitted (2017)

23AABC Mainz | 31.. January 2017

Summary

o The single step transformation of sulphur to Li2S2/Li2S and vice-versa during the

discharge/charge process was realized in a cocnut-based carbon and explained by

analyzing the subsurface using XPS.

o Mg-S batteries need non-nucleophilic electrolytes. prepared from Mg amide

compounds. A new Cl-free electrolyte shows very good performance.

o Major issues: overpotentials, capacity degradation upon cycling (polysulfide)

o Organic electrode based on porphyrins can deliver mediocre capacities at very high

rates. for several 1000 cycles.

24AABC Mainz | 31.. January 2017

Christian Baur

Bhaghavathi Parambath Vinayan

Christian Bonatto Minella

Tobias Braun

René Breitenbach

Musa Ali Cambaz

Christina Danetzki

Bijoy Kumar Das

Ping Gao

Fabienne Gschwind

Xiu-Mei Lin

Helen Maria Joseph

Anji Reddy Munnangi

Maxim Pfeifer

Julia Rinck

Nele SchwarzburgerDan Sandbeck

Duc Tho Thieu

Sebastian Wenzel

Le Zhang

Zijian Zhao

Zhirong Zhao-Karger

Maximilian Fichtner

The Group

from KIT:modelling:

J. Mueller

M. Ruben Z. Chen

25AABC Mainz | 31.. January 2017

Thank you !

http://www.hiu-batteries.de/de/

Additional slides

27AABC Mainz | 31.. January 2017

Mono- and multivalent elements and relevant properties for battery applications.

D. Linden, T.B. Reddy, ed., Handbook of Batteries, 4th Edition, McGraw-Hill, New York, 2010

M. Thackeray et al.,, Energy Environ. Sci. 5 (2012) 7854

For coordination number 6), from R. D. Shannon. Acta Crystallogr A. 32 (1976) 751–767.

David R. Lide, ed., CRC Handbook of Chemistry and Physics, 89th Edition (Internet Version 2009),

Motivation / Energy Density, Abundance

ElementCharge

of ion

crystal

ionic

radii

/pm

Earth crustal

abundance/ppm

by weight

Price

(pure)

US$ per

100g

specific capacityPotential

vs. NHE/VmA·h·g-1 mA·h·cm-3

Li 1 9020 (+183 µg/L in

seawater)27 3862 2047 -3.04

Na 1 11624000 (+10.8 g/L

in seawater)25 1166 1130 -2.71

Mg 2 86 23300 3.7 2206 3840 -2.37

Ca 2 114 41500 20 1338 2006 -2.87

Zn 2 88 70 5.3 820 6845 -0.76

Al 3 68 82300 15.7 2980 8050 -1.66

Cl -1 167145 (+19.4 g/L in

seawater)0.1 - -

(-1.5-2 V)

used only as

shuttle

28AABC Mainz | 31.. January 2017

Electrochemical pairs of Li-ion, post-Li ion and post-Li systems

Gravimetric energy density (Wh/kg)

Li-ion

Ca/CoF3

Chlorides

Mg/CuCl2

Ca/CuCl2

Li/CuCl2

Fluorides

La/CoF3

Ca/CoF3

Li/FeF3

Li/CuF2

LiC6 / NMC

Vo

lum

etr

ice

ne

rgy

de

nsity

(Wh

/l)

Mg

batteries

Metal

Sulphur

Li/S

Mg/S

Metal-

Air

Li/O2

Mg/O2

Zn/O2Na/O2

Na-ion

Hard-C /

NaNMC

Li rich fcc materials

Li2VO2F

Li2CrO2F

29AABC Mainz | 31.. January 2017

Chloride Ion Batteries

VOCl as cathode

P. Gao, M. Fichtner et al., Angew. Chemie Int. Ed. 53 (2016) 4285

0 30 60 90 120 150 180

1,2

1,6

2,0

2,4

2,8

1st10th

Volta

ge / V

Capacity (mAh/g)

@ 0.5 C rate

0 10 20 30 40 50

30

60

90

120

150

180

2 C0.5 C1 C

1 C0.5 C

Capacity (

mA

h/g

)

Cycle number

The theoretical capacity is 261 mAh g-1 based on 1 mol e-

transfer;

< 0.7 e- should be kept in practice to avoid structural

collapse

Rate performance

0.5 mol PP14Cl in PC as electrolyte

Mixed intercalation and conversion mechanism

stable in air

30AABC Mainz | 31.. January 2017

CSC composite data (XRD , BET)

31AABC Mainz | 31.. January 2017

Fading mechanism

Sulphur 163.9 eV

Sulphate 169.5 eV

Li2S2

162.2 eV

Sulphur 163.9 eV

Sulphur 163.9 eV

Sulphur 163.9 eV

Li2S2

162.2 eV

Li2S2 162.2 eV

Li2S

160.9 eV

Ex-situ XPS measurements of cathodes after 10 and 400 discharge/charge cycles

32AABC Mainz | 31.. January 2017

XP spectra in the S 2p region recorded for (a) pristine sulphur, (b) CSC-S

composite, (c) pristine Li2S and (d) Na2S2.

Sulphur 163.9 eV

Li2S 160.7 eV

Sulphur 163.9 eV

XP spectra in the S 2p region recorded for pristine samples

33AABC Mainz | 31.. January 2017

Coconut shell

Po

rou

s c

arb

on

Carbon-Sulphur

composite

Coconut Shell derived Carbon

Coconut Shell derived Carbon-Sulphur composite

CSC

CSC-S

Synthesis of Coconut Shell derived Carbon-Sulphur (CSC-S) composite

34AABC Mainz | 31.. January 2017

(ref. Avicenne Energy Studies, 2016)

Cathode

active materials, worldwide market

Cobalt

expensive, co-mined with Ni; children labour

Strong increase in LIB production expected

Reality overhauls predictions

Motivation / Element supply

Anode:

Cell needs 100 – 160 g Li / kWh

Germany: 40 Mio cars running on LIB will consume 15 x the current worldwide Li

production. Long run: will there be a cost-effective recycling?

35AABC Mainz | 31.. January 2017

Zh. Zhao-Karger, M. Fichtner et al., Adv. Energy Mater. 2014, 1401155

Magnesium–sulfur battery

36AABC Mainz | 31.. January 2017