Electrolyte Compositions For Rechargeable Lithium Ion Batteries

Patent metadata

Field	Value
Publication number	US-2017317385-A1
Application number	US-201415533668-A
Country	US
Kind code	A1
Filing date	Dec 17, 2014
Priority date	Dec 17, 2014
Publication date	Nov 2, 2017
Grant date	—

Abstract

One or more additives are selected from the group consisting of a) tertiary amines, b) amides, c) pyridine compounds, d) organophosphorus compounds, e) phosphonitrilic compounds, f) organoboron compounds, g) borate salts, h) anhydrides and i) nitrites are effective towards preventing color formation in electrolyte compositions for secondary Li ion batteries, which electrolyte compositions contain an organic solvent, one or more lithium salts and one or more cyclic sulfate additives. Advantageously, a combination of one or more compounds selected from the group consisting of a) tertiary amines, b) amides, c) pyridine compounds, d) organic phosphorus compounds and e) phosphonitrilic compounds is employed together with one or more compounds selected from the group consisting of f) organoboron compounds, g) borate salts, h) anhydrides and i) nitriles.

First claim

1 . An electrolyte composition stabilized against color formation comprising an organic solvent, one or more lithium salts, one or more cyclic sulfate additives and
one or more additives selected from the group consisting of a) tertiary amines, b) amides, c) pyridine compounds, d) organophosphorus compounds, e) phosphonitrilic compounds, f) organoboron compounds, g) borate salts, h) anhydrides and i) nitriles,
where the cyclic sulfate additives are of formula

where the R groups together are hydrocarbylene.

2 . A composition according to claim 1 where the cyclic sulfate additives are selected from the group consisting of 1,3,2-dioxathiolane 2,2-dioxide, 1,3-propanediol cyclic sulfate, propylene sulfate (4-methyl-1,3,2-dioxathiolane 2,2-dioxide), 4-ethyl-1,3,2-dioxathiolane 2,2-dioxide and 4-propyl-1,3,2-dioxathiolane 2,2-dioxide.

3 . A composition according to claim 1 where the organic solvent comprises one or more solvents selected from the group consisting of organic carbonates, sulfones, sulfoxides, esters, lactones, ethers and glymes.

4 . A composition according to claim 1 where the organic solvent comprises one or more organic carbonates selected from the group consisting of ethylene carbonate, propylene carbonate, trimethylene carbonate, 1,2-butylene carbonate, dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, dipropyl carbonate, vinylene carbonate, difluoroethylene carbonate and monofluoroethylene carbonate.

5 . A composition according to claim 1 where the lithium salts are selected from the group consisting of LiPF 6 , LiClO 4 , LiN(CF 3 SO 2 ) 2 , LiAsF 6 and LiCF 3 SO 3 and where the lithium salts in total are present in the organic solvent at a level of from about 0.5 M to about 2.5 M.

6 . A composition according to claim 1 comprising one or more additives selected from the group consisting of
a) tertiary amines of formula NR 1 R 2 R 3 where R 1 , R 2 and R 3 are each hydrocarbyl or where R 1 and R 2 and/or R 1 and R3 and/or R 2 and R 3 together are hydrocarbylene;
b) phosphoramides or organic amides of formula R 1 R 2 NC(O)R 3 where R 1 , R 2 and R 3 are each hydrogen or hydrocarbyl or R 1 and R 2 and/or R 1 and R 3 and/or R 2 and R 3 together are hydrocarbylene;
c) pyridine compounds of formula

where Rx is hydrogen, halogen or hydrocarbyl;
d) organophosphorus compounds of formula

where R 1 , R 2 and R 3 are independently hydrocarbyl or R 1 and R 2 and/or R 1 and R 3 and/or R 2 and R 3 together are hydrocarbylene;
e) phosphonitrilic compounds of formula

where R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are independently alkoxy, halogen or hydrocarbyl;
f) organoboron compounds of formula

where Ry is hydrogen, alkoxy or hydrocarbyl and R1′, R2′ and R3′ are hydrogen or hydrocarbyl;
g) borate salts;
h) phosphonic anhydrides or anhydrides of formula

where R 1 and R2 are independently hydrocarbyl or together are hydrocarbylene; and
i) nitriles of formula
R 1 —CN or NC—R z -CN

where R1 is hydrocarbyl and Rz is hydrocarbylene.

7 . A composition according to claim 6 comprising one or more additives selected from the group consisting of
a) triethylamine, tributylamine, N,N,N′,N″,N″-pentamethyldiethylenetriamine, N,N,N′,N″,N′″,N″″-hexamethyltriethylenetetraamine, N,N,N′,N′-tetramethylethylenediamine or triethylenediamine;
b) N,N-dimethyl acetamide, N,N-dimethyl-trifluoroacetamide, N,N-diethyl-trifluoroacetamide, N-methyl-trifluoracetamide, 1-methyl-2-pyrrolidinone or hexamethylphosphoramide;
c) pyridine, 2,2-dipyridyl, 4,4′-dipyridyl, 4-bromopyridine, 3-chloropyridine, 2-vinylpyridine or 4-tert-butylpyridine;
d) triphenylphosphine, triethylphosphine, tripropylphosphine, triisobutylphosphine, trihexylphosphine, trioctylphosphine, tributylphosphine, tris-pentafluorophenylphosphine or tris(4-fluorophenyl) phosphine;
e) hexamethoxycyclotriphosphazene, phosphonitrilic chloride trimer or phosphonitrilic fluoride trimer;
f) 4,4,6-trimethyl-1,3,2-dioxaborinane, 2-methoxy-4,4,6-trimethyl-1,3,2-dioxaborinane, 2-ethoxy-4,4,6-trimethyl-1,3,2-dioxaborinane, 2-isopropoxy-4,4,6-trimethyl-1,3,2-dioxaborinane, 2-butoxy-4,4,6-trimethyl-1,3,2-dioxaborinane, vinylboronic acid 2-methyl-2,4-pentanediol ester, phenylboronic acid neopentylglycol ester or phenylboronic acid 1,3-propanediol ester;
g) alkali metal salts of borates selected from the group consisting of orthoborate, tetrahydroxyborate, tetraborate, tetraphenylborate, [B(3,5-(CF 3 ) 2 C 6 H 3 ) 4 ] − , B(C 2 O 4 ) 2 − , difluoro(oxalato)borate, di(trifluoroacetato)oxalatoborate, B(C 6 F 5 ) 4 − and BF 4 − ;
h) succinic anhydride, glutaric anhydride, phthalic anhydride, acetic anhydride, maleic anhydride, naphthalic anhydride, propionic anhydride, citraconic anhydride, butyric anhydride, 3,4,5,6-tetrahydrophthalic anhydride, isatoic anhydride, valeric anhydride or propylphosphonic anhydride; and
i) acetonitrile, propionitrile, butyronitrile, isobutyronitrile, 1,2-dicyanoethane, succinonitrile, 1,5-dicyanopentane, hexanedinitrile (adiponitrile), glutaronitrile or fumaronitrile.

8 . A composition according to claim 1 where the cyclic sulfate compounds together with the compounds a)-i), in total, are present from about 0.01 to about 15%, by weight, based on the total weight of the electrolyte composition and where the weight:weight ratio of the one or more cyclic sulfate compounds to the one or more additives a)-i) is from about 1:9 to about 9:1.

9 . A composition according to claim 1 comprising
one or more compounds selected from the group consisting of a) tertiary amines, b) amides, c) pyridine compounds, d) organic phosphorus compounds and e) phosphonitrilic compounds
and
one or more compounds selected from the group consisting of f) organoboron compounds, g) borate salts, h) anhydrides and i) nitriles.

10 . A composition according to claim 9 where the weight:weight ratio of the one or more compounds selected from the group consisting of a) to e) to the one or more compounds selected from the group consisting f) to i) is from about 1:9 to about 9:1.

11 . A composition according to claim 1 further comprising one or more further additives selected from the group consisting of formulae (1) to (12)

where
R 11 and R 12 are independently hydrogen, halogen, alkyl or haloalkyl;
R 13 , R 14 , R 15 and R 16 are independently hydrogen, halogen, alkyl, haloalkyl, vinyl or allyl, where at least one of R 13 to R 16 is vinyl or allyl;
R 17 is hydrogen or alkyl;
R 21 to R 26 are independently hydrogen, halogen, alkyl or haloalkyl, where at least one of R 21 to R 26 is halogen or haloalkyl;
R 27 to R 30 are independently hydrogen, halogen, alkyl or haloalkyl, where at least one of R 27 to R 30 is halogen or haloa

Assignees

• Basf Corp

Inventors

• Zhang Zhenghua
• Hu Xueshan
• Zhang Jianfei

Classifications

• H01M10/0569

  characterised by the solvents · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2300/004

  Three solvents · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title

• H01M10/0568

  characterised by the solutes · CPC title