Lithium secondary battery

Patent metadata

Field	Value
Publication number	US-11063290-B2
Application number	US-201816467186-A
Country	US
Kind code	B2
Filing date	Jun 21, 2018
Priority date	Jun 21, 2017
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A lithium secondary battery prepared to a negative electrode free battery, and forming lithium metal on a negative electrode current collector through charge. The lithium secondary battery forms lithium metal while being blocked from the atmosphere, and since production of a surface oxide layer (native layer) formed on an existing negative electrode is fundamentally blocked, resulting battery efficiency and lifetime property decline may be prevented.

First claim

The invention claimed is:

1. A lithium secondary battery, comprising
a positive electrode, a negative electrode, and a separator and an electrolyte interposed therebetween,
wherein, in the negative electrode, metal particles are formed on a negative electrode current collector, and
lithium metal moved from the positive electrode is formed on the negative electrode current collector in the negative electrode through charge,
wherein the metal particles are at least one metal or metalloid selected from the group consisting of silver, gold, magnesium, molybdenum, sodium, osmium, lead, palladium, platinum, plutonium, rubidium, rhodium, ruthenium, selenium, strontium, tantalum, tellurium, uranium, tungsten, and zirconium,
wherein the metal particles are included in a content of 0.1% by weight to 40% by weight with respect to the negative electrode current collector.

2. The lithium secondary battery of claim 1 , wherein the lithium metal which is formed on the negative electrode current collector is formed through one-time charge in a voltage range of 4.5 V to 2.5 V.

3. The lithium secondary battery of claim 1 , wherein the negative electrode further comprises a protective layer formed on a surface in contact with the separator.

4. The lithium secondary battery of claim 3 , wherein the protective layer comprises any one or more of a lithium ion conducting polymer and an inorganic solid electrolyte.

5. The lithium secondary battery of claim 4 , wherein the lithium ion conducting polymer is at least one selected from the group consisting of polyethylene oxide (PEO), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP).

6. The lithium secondary battery of claim 4 , wherein the inorganic solid electrolyte is at least one selected from the group consisting of thio-LISICON (Li 3.25 Ge 0.25 P 0.75 S 4 ), Li 2 S—SiS 2 , LiI—Li 2 S—SiS 2 , LiI—Li 2 S—P 2 S 5 , LiI—Li 2 S—P 2 O 5 , LiI—Li 3 PO 4 —P 2 S 5 , Li 2 S—P 2 S 5 , Li 3 PS 4 , Li 7 P 3 S 11 , Li 2 O—B 2 O 3 , Li 2 O—B 2 O 3 —P 2 O 5 , Li 2 O—V 2 O 5 —SiO 2 , Li 2 O—B 2 O 3 , Li 3 PO 4 , Li 2 O—Li 2 WO 4 —B 2 O 3 , LiPON, LiBON, Li 2 O—SiO 2 , LiI, Li 3 N, Li 5 La 3 Ta 2 O 12 , Li 7 La 3 Zr 2 O 12 , Li 6 BaLa 2 Ta 2 O 12 , Li 3 PO (4−3/2w) Nw (w is w<1) and Li 3.6 Si 0.6 P 0.4 O 4 .

7. The lithium secondary battery of claim 4 , wherein the protective layer further comprises one or more types of lithium salts selected from the group consisting of LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, LiSCN, LiC(CF 3 SO 2 ) 3 , (CF 3 SO 2 ) 2 NLi, (FSO 2 ) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenylborate and lithium imide.

8. The lithium secondary battery of claim 4 , wherein the protective layer has a thickness of 10 nm to 50 μm.

9. The lithium secondary battery of claim 1 , wherein the metal particles are formed on the negative electrode current collector and the metal particles are separated from each other with a gap of greater than or equal to 1 nm and less than 10 μm.

10. The lithium secondary battery of claim 1 , wherein the positive electrode includes one or more types of positive electrode active materials selected from the group consisting of LiCoO 2 , LiNiO 2 , LiMnO 2 , LiMn 2 O 4 , Li(Ni a Co b Mn c )O 2 (0<a<1, 0<b<1, 0<c<1, a+b+c=1), LiNi 1−Y Co Y O 2 , LiCo 1−Y Mn Y O 2 , LiNi 1−Y Mn Y O 2 (herein, 0≤Y<1), Li(Ni a Co b Mn c )O 4 (0<a<2, 0<b<2, 0<c<2, a+b+c=2), LiMn 2−z Ni z O 4 , LiMn −z Co z O 4 (herein, 0<Z<2), Li x M y Mn 2−y O 4−z A z (herein, 0.9≤x≤1.2, 0<y<2, 0≤z<0.2, M is one or more of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Ti and Bi, A is one or more anions with valency of −1 or −2), Li 1+a Ni b M′ 1−b O 2−c A′ c (0≤a≤0.1, 0≤b≤0.8, 0≤c<0.2, M′ is at least one 6-coordinated stable element, and A′ is one or more anions having valency of −1 or −2.), LiCoPO 4 and LiFePO 4 .

11. The lithium secondary battery of claim 1 , wherein the positive electrode includes a lithium metal compound represented by any one of the following Chemical Formulae 1 to 8:
Li 2 Ni 1−a M 1 a O 2   [Chemical Formula 1]

in the formula, a is 0≤a<1, and M 1 is one or more types of elements selected from the group consisting of Mn, Fe, Co, Cu, Zn, Mg and Cd;
Li 2+b Ni 1−c M 2 c O 2+d   [Chemical Formula 2]

in the formula, −0.5≤b<0.5, 0≤c≤1, 0≤d<0.3, and M 2 is one or more types of elements selected from the group consisting of P, B, C, Al, Sc, Sr, Ti, V, Zr, Mn, Fe, Co, Cu, Zn, Cr, Mg, Nb, Mo and Cd;
LiM 3 e Mn 1−e O 2   [Chemical Formula 3]

in the formula, e is 0≤e<0.5, and M 3 is one or more types of elements selected from the group consisting of Cr, Al, Ni, Mn and Co;
Li 2 M 4 O 2   [Chemical 4]

in the formula, M 4 is one or more types of elements selected from the group consisting of Cu and Ni;
Li 3+f Nb 1−g M 5 g S 4−h   [Chemical Formula 5]

in the formula, −0.1≤f≤1, 0≤g≤0.5, −0.1≤h≤0.5, and M 5 is one or more types of elements selected from the group consisting of Mn, Fe, Co, Cu, Zn, Mg and Cd;
LiM 6 i Mn 1−i O 2   [Chemical Formula 6]

in the formula, i is 0.05≤i<0.5, and M 6 is one or more types of elements selected from the group consisting of Cr, Al, Ni, Mn and Co;
LiM 7 2j Mn 2−2j O 4   [Chemical Formula 7]

in the formula, j is 0.05≤j<0.5, and M 7 is one or more types of elements selected from the group consisting of Cr, Al, Ni, Mn and Co;
Li k −M 8 m −N n   [Chemical Formula 8]

in the formula, M 8 represents an alkaline-earth metal, k/(k+m+n) is from 0.10 to 0.40, m/(k+m+n) is from 0.20 to 0.50, and n/(k+m+n) is from 0.20 to 0.50..

12. The lithium secondary battery of claim 1 , wherein the lithium metal formed on the negative electrode current collector is a lithium metal layer having a thickness of 50 nm to 100 μm.

Assignees

• Lg Chemical Ltd

Inventors

• Park Eunkyung
• Jang Minchul
• Son Byoungkuk
• Choi Junghun
• Kang Donghyeon
• Jung Bora

Classifications

• H01M4/667

  in the form of layers, e.g. coatings · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/366

  as layered products · CPC title

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title