<2023> 황화물계 고체전해질 제조기술분석 및 시장 전망
(대기안정형 sulfide계 중심)
현재의 리튬이온전지의 큰 약점인 안전성을 획기적으로 향상시킬 차세대전지로서 고체전해질을 적용한 전고체전지가
떠오르고 있다. 전고체전지의 장점은 「우수한 안전성」, 「높은
에너지밀도」, 「고출력」, 「넓은 사용온도」, 「단순한 전지구조」 등을 꼽을 수 있으며, 전고체전지의 핵심소재는
단연 고체전해질로서, 전지에서의 특성이나 파급력에서 현재는 황화물계 고체전해질이 가장 앞서 있다고 말할
수 있다.
SNE Research의 전망에 따르면 글로벌 전고체전지 시장규모는 2022년 약 2,750만 달러에서 연평균 180%의 높은 성장률을 나타내어 2030년 약 400억 달러의 큰 시장을 형성할 것으로 전망된다. 전지용량면에서는
‘30년 ~149GWh, ‘35년엔 ~950GWh의 시장이 전망되며 전체 전지의 약 10%를 전고체전지가
차지할 것으로 전망하고 있으며, 이 중에서 황화물계 고체전해질은 ‘30년
43GWh, ‘35년 494GWh를 차지할 것으로 전망하고
있다.
’21.6월 전고체전지의 선행 개발자인 도요타가 전고체전지를
탑재한 EV로 도로시험주행까지 마쳤으나, 동년 9월 발표에선 고체전해질과 활물질의 gap발생으로인한 사이클수명 저하
문제로 인해 이를 해결하기 위한 새로운 고체전해질 물질 개발의 필요성이 대두되었고, 고체전해질 자체
및 활물질과의 계면문제 등 내구성문제 해결이 쉽지 않음을 보여주었다.
하지만, 지난 6.13일
도요타는 「TOYOTA Technical Workshop 2023」을 통해 전고체전지를 탑재한 EV를 ‘27~’28년께 상용화한다는 목표를 내놓음으로써 전고체전지의
내구성 문제를 해결한 것으로 생각된다. 한편, 국내 배터리
3사도 이전부터 각각 전고체전지를 개발해 오고 있으며, 삼성SDI는 27년부터 SK On은
27년부터, LG엔솔은 30년이후로
양산을 발표한 바 있다.
현재, 전고체전지용 고체전해질로서 황화물계가 가장 활발하게 적용되고
있지만, 다음의 크게 두가지 문제를 해결하지 않으면 안 된다.
첫째는 충방전수명이다. 전기차에 탑재해 상용화하려면 충방전수명을
수천 사이클 이상으로 끌어 올려야 하는데, 현재는 수십~수백
사이클에 머물러 있다. 둘째는 제조비용을 낮추는 것인데 현재의 전고체전지의 제조비용은 kWh당 기존 LiB에 비해 4배
~ 25배 정도 비싸기 때문에 상용화의 큰 걸림돌이 되고 있다.
결국, 전고체전지 상용화의 핵심은 장수명과 저가격이 가능한 황화물계
고체전해질의 개발 및 제조기술개발에 있다고 말할 수 있다.
본 리포트는 황화물계 고체전해질의 개발에 있어서 지금까지 진행되어온 고체전해질 합성 및 전지에의 적용까지
폭 넓게 기술하고 있으며, 최근에 큰 흐름의 하나인 수분에의 저항력이 향상된 대기안정형 황화물계 고체전해질, 특히 argyrodite계의 합성 및 응용에 이르기까지 deep dive하게 기술하고 있으며, 더 나아가, 황화물계 고체전해질의 출발물질인 황화리튬(Li2S)의
저가격 합성법과 해당 업체의 제품과 현황을 폭 넓게 다루고 있다.
마지막으로, 황화리튬과 황화물계 고체전해질을 생산하고 있는 업체가
출원한 특허 및 라이선스특허의 권리범위와 실시예까지 상세하게 분석하였으며, 해당 업체의 최신현황과 가장
활용성이 예상되는 Argyrodite 및 LGPS계 특허를
심도 있게 분석하여 황화물계 고체전해질을 개발하거나 다루는 분들에게 큰 도움이 될 것이라 생각합니다.
본 보고서의 Strong Point는 다음과 같다.
①
고체전해질을 둘러싼 최근의 기술문제 및 해결방안 내용
②
반고체(semi-solid)전해질 개발현황 및
이를 적용한 전지까지 범위 확대
③
황화리튬 및 황화물계 고체전해질의 합성 및 특성 분석 내용
④
황화물계 고체전해질의
제조업체별 최신동향 및 LPSCl계, LGPS계 주요 특허
분석
⑤
최근의 핫
이슈인 대기안정형 황화물계 고체전해질 개발 및 현황
⑥
황화물계 고체전해질
및 황화리튬 생산업체 망라
[LPSCl계 주요 특허의 분석]
목 차
1. 고체전해질 개요 및
시장전망
1.1. 서론··································································································································
9
1.1.1. 고체전해질의
분류 및 역사 ······························································· 10
1.1.2. 고체전해질
및 전고체전지 개발현황················································ 15
1.1.3. 무기계
고체전해질의 주요 이슈 ······················································· 22
1.1.4. 전고체전지를
둘러싼 기술문제 및 해결방안······························ 26
1.1.5. 반고체(하이브리드)전해질 및 이를 적용한 전지······················ 30
1.1.6. 전해질
종류별 시장 전망········································································· 34
2. 전고체전지용 고체전해질
2.1. 서론
···························································································································· 37
2.1.1. 고분자계
고체전해질················································································
36
2.1.2. 무기계
고체전해질·····················································································
40
2.1.2.1.
산화물계···························································································
40
2.1.2.2.
인산염계···························································································
42
2.1.2.3.
황화물계···························································································
43
2.1.2.4.
복합 고체전해질············································································ 48
2.1.2.
계면························································································································ 51
2.1.3.1. 양극-고체 전해질 계면······························································ 53
2.1.3.2. 리튬음극-고체 전해질 계면···················································· 55
2.1.3.3. 입자간 계면······················································································ 56
2.1.4.
전해질 기술에 대한 요구사항······························································· 58
3. 황화리튬 (Li2S)
3.1. 서론
···························································································································· 59
3.1.1. 고상
합성법의 종류···················································································
59
3.1.2. 액상
합성법의 종류····················································································· 62
3.2. Li2S 합성······················································································································· 64
3.2.1.
Lab scale 합성·······························································································
64
3.2.2. 산업적
Li2S생산 및 재처리···································································
66
3.2.1.1.
Li2S의 산업적 생산·····································································
66
3.2.1.2.
Li2S제조시 원재료 예상가격················································· 67
4. 황화물계 고체전해질
4.1. 서론·······························································································································
70
4.1.1.
LiPSCl (Argyrodite_LiPSX)········································································
71
4.1.1.1.
Li argyrodite 합성(기계적 milling방법)··························
76
4.1.1.2.
Li argyrodite 합성(기계적 milling+
post annealing방법)····
78
4.1.1.3.
Li argyrodite 합성(고상 소결법)·········································
80
4.1.1.4.
Li argyrodite 합성(액상 합성법)·········································
82
4.1.1.5.
Li argyrodite의 전지에의 적용············································ 88
4.1.1.5.1.
Li7-xPS6-xClx 조성 합성····················································
88
4.1.1.5.2. AIMD 시뮬레이션·····························································
89
4.1.1.5.3. 셀 제조···················································································
90
4.1.1.5.4. 셀 적용 결과······································································
90
4.1.1.5.5. 전지 적용 결론······························································
103
4.1.2.
LiPS 계 (Li2S-P2S5 외)············································································
104
4.1.2.1.
LiPS계 합성···················································································
105
4.1.2.2.
LiPS계 전기화학적 특성·······················································
107
4.1.3. LixMPxSx
(M: Ge, Sn, Si, and Al)계 ················································· 108
4.1.3.1.
LixMPxSx 계 합성·······································································
109
4.1.3.2.
LixMPxSx 전기화학적 특성···················································
111
5. 대기안정형 황화물계
고체전해질
5.1. 서론
························································································································· 113
5.1.1. Argyrodite-oxysulfides
(LiPSOCl)
5.1.1.1.
합성 방법······················································································
114
5.1.1.2.
구조 및 구성 분석··································································
115
5.1.1.3.
전지에의 적용 ········································································· 118
5.1.2. xLi4SnS4•(1-x)Li3PS4
계 고체전해질················································
120
5.1.2.1.
고체전해질 합성·······································································
121
5.1.2.2.
고체전해질 특성 분석··························································
121
5.1.2.3.
고체전해질 제조 및 공기안정성 평가·······················
121
5.1.2.4.
고체전해질 평가 결론··························································
123
5.1.3. Sb-Substituted
Li4SnS4 계 고체전해질
5.1.3.1.
고체전해질 합성·······································································
124
5.1.3.2.
고체전해질 구조 분석···························································
125
5.1.3.3.
고체전해질의 공기안정성 평가·······································
127
5.1.3.4.
고체전해질의 특성 분석······················································
127
5.1.3.5.
고체전해질 평가 결론···························································
132
5.2. 황화물계 고체전해질(Sulfide Solid Electrolyte:
S-SE)의 화학적 안정성
5.2.1. 화학적 안정성의 개요···········································································
132
5.2.2. 황화물계 고체전해질의 화학적 안정성····································· 134
5.2.2.1. 습한 분위기에서의 S-SE의
화학적 안정성·············
134
5.2.2.2. 용매와 바인더 존재 시S-SEs의 화학적 안정성···· 137
5.2.2.3. 용매와의 상용성(compatibility)
···································· 139
5.2.2.4. 바인더와의 상용성··································································
145
5.2.3. 황화물계 고체전해질의 화학적 안정성 향상을 위한 전략······ 148
5.2.3.1. 습한 분위기에서 S-SE의
보호·········································
149
5.2.3.1.1. 첨가제 사용······································································
149
5.2.3.1.2. 루이스 산염기(HSHB)
·············································· 155
5.2.3.1.3.
Core-shell설계·································································
161
5.2.3.1.4.
합성 방법···········································································
163
5.2.3.2. S-SE 합성 시 용매의 선택·················································
165
5.2.3.2.1. 극성이 낮은 용매의 적용········································
165
5.2.3.3. S-SEs 및 바인더 선택···························································
171
5.2.3.4. 화학적 안정성 향상을 위한 전략 summary·········· 179
5.2.3.5. 향후 전망······················································································
181
6. 황화물계 고체전해질
주요 특허분석 및 업체동향
6.1. 서론····························································································································
184
6.1.1.
LiPSCl 원천특허·························································································
184
6.1.2. 황화물계
고체전해질 특허 및 논문동향···································
185
6.1.3 LPSX
황화물계 선행특허 분석··························································
189
6.1.4 LGPS
황화물계 특허 분석····································································
201
6.1.5
Toyota 자동차의 EV 및 차세대 전지기술 개발방향··········· 205
6.2. 황화물계 고체전해질 제조업체································································
207
6.2.1. 이데미츠 코산····························································································
207
6.2.2. 미쯔이 금속광업·······················································································
210
6.2.3. 후쿠카와 기계금속··················································································
214
6.2.4. 후지필름 와코 ·························································································· 216
6.2.5. Solid Power···································································································
218
6.2.6. 포스코 JK 솔리드
솔루션····································································
221
6.2.7. 에코프로비엠·······························································································
224
6.2.8. 대주전자재료·······························································································
226
6.2.9. 씨아이에스(CIS)
······················································································· 230
6.2.10. 솔리비스······································································································
234
6.2.11. 인캠스(INCHEMS) ················································································ 238
6.2.12. 이엔플러스(ENplus) ············································································ 241
6.2.13. 동화일렉트로라이트·············································································
244
6.2.14. 한솔케미칼·································································································
246
6.2.15. 롯데에너지머티리얼즈(구 일진머티리얼즈) ························ 248
6.2.16. 이수화학(Li2S
제조업체) ·································································· 254
6.2.17. 정석케미칼(Li2S
제조업체) ····························································· 256
6.2.18. 레이크머티리얼즈(Li2S 제조업체) ·············································· 260
6.2.19. 천보················································································································
262
6.2.20. 나노캠프······································································································
263
6.2.21. 비이아이랩(BEILab) ············································································· 264
6.2.22. NEI Corporation······················································································
267
6.2.23. Albermale-Universität Siegen(Li2S 제조업체) ····················· 269
6.2.24. Lorad Chemical Corp. (Li2S
제조업체)······································
272
6.2.25. AMG Lithium GmbH (Li2S
제조업체) ······································· 274
6.2.26. Stanford Advanced Materials (Li2S
제조업체) ···················· 276
6.2.27. Ganfeng Lithium (Li2S 제조업체) ··············································· 277
6.2.28. Hubei XinRunde Chemical (Li2S
제조업체) ·························· 280
6.2.29. Hangzhou Kaiyada (Li2S 제조업체) ·········································· 281
6.2.30. Chengdu Hipure ··················································································· 282
6.2.31. Ampcera·······································································································
284
6.2.32. MTI Corp. ·································································································· 286
References·················································································································
287