Abstract
The framework compounds M2(SO4)3 with M = (Ti Fe), (V Fe), Fe and LixM2(PO4)3 with M = Ti, (V Fe), Fe, were synthesized and electrochemically characterized by the coin-cell method. Use of larger (XO4)n- polyanions not only allows fast Li+-ion conduction in an open three-dimensional framework that is selective for the working alkali ion on discharge; it also stabilizes operative redox potentials Fe3+/Fe2+, Ti4+/Ti3+ and V3+/V2+ that give open-circuit voltages Voc > 2.5 Vas well as access to V4+/V3+, Ti3+/Ti2+ and Fe2+/Fe+ couples. Separation of the V4+/V3+ and V3+/V2+ couples were found to be 2.0 V. Fe2(SO4)3 has both monoclinic and rhombohedral modifications that give a flat open-circuit voltage Voc = 3.6 V versus Li and a reversible capacity for ∼ 1.8 lithium atoms per formula unit. LixFe2(SO4)3 shows an abrupt voltage drop occurring for x > 2 that can be held in check by the addition of buffers such as Li3Fe2(PO4)3, FeV(SO4)3 and LiTi2(PO4)3. Changing the polyanion group from (SO4)2- to (PO4)3- in these framework compounds decreases the redox potentials from 3.2 to 2.5 V for the Ti4+/Ti3+ couple, 2.5 to 1.7 V for the V3+/V2+ couple and 3.6 to 2.8 V for the Fe3+/Fe2+ couple. Comparative advantages and disadvantages of framework cathodes for Li rechargeable battery applications are discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 1-10 |
| Number of pages | 10 |
| Journal | Solid State Ionics |
| Volume | 92 |
| Issue number | 1-2 |
| Publication status | Published - Nov 1 1996 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics
Cite this
Synthesis, redox potential evaluation and electrochemical characteristics of NASICON-related-3D framework compounds. / Nanjundaswamy, K. S.; Padhi, A. K.; Goodenough, J. B.; Okada, Shigeto; Ohtsuka, H.; Arai, H.; Yamaki, J.
In: Solid State Ionics, Vol. 92, No. 1-2, 01.11.1996, p. 1-10.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synthesis, redox potential evaluation and electrochemical characteristics of NASICON-related-3D framework compounds
AU - Nanjundaswamy, K. S.
AU - Padhi, A. K.
AU - Goodenough, J. B.
AU - Okada, Shigeto
AU - Ohtsuka, H.
AU - Arai, H.
AU - Yamaki, J.
PY - 1996/11/1
Y1 - 1996/11/1
N2 - The framework compounds M2(SO4)3 with M = (Ti Fe), (V Fe), Fe and LixM2(PO4)3 with M = Ti, (V Fe), Fe, were synthesized and electrochemically characterized by the coin-cell method. Use of larger (XO4)n- polyanions not only allows fast Li+-ion conduction in an open three-dimensional framework that is selective for the working alkali ion on discharge; it also stabilizes operative redox potentials Fe3+/Fe2+, Ti4+/Ti3+ and V3+/V2+ that give open-circuit voltages Voc > 2.5 Vas well as access to V4+/V3+, Ti3+/Ti2+ and Fe2+/Fe+ couples. Separation of the V4+/V3+ and V3+/V2+ couples were found to be 2.0 V. Fe2(SO4)3 has both monoclinic and rhombohedral modifications that give a flat open-circuit voltage Voc = 3.6 V versus Li and a reversible capacity for ∼ 1.8 lithium atoms per formula unit. LixFe2(SO4)3 shows an abrupt voltage drop occurring for x > 2 that can be held in check by the addition of buffers such as Li3Fe2(PO4)3, FeV(SO4)3 and LiTi2(PO4)3. Changing the polyanion group from (SO4)2- to (PO4)3- in these framework compounds decreases the redox potentials from 3.2 to 2.5 V for the Ti4+/Ti3+ couple, 2.5 to 1.7 V for the V3+/V2+ couple and 3.6 to 2.8 V for the Fe3+/Fe2+ couple. Comparative advantages and disadvantages of framework cathodes for Li rechargeable battery applications are discussed.
AB - The framework compounds M2(SO4)3 with M = (Ti Fe), (V Fe), Fe and LixM2(PO4)3 with M = Ti, (V Fe), Fe, were synthesized and electrochemically characterized by the coin-cell method. Use of larger (XO4)n- polyanions not only allows fast Li+-ion conduction in an open three-dimensional framework that is selective for the working alkali ion on discharge; it also stabilizes operative redox potentials Fe3+/Fe2+, Ti4+/Ti3+ and V3+/V2+ that give open-circuit voltages Voc > 2.5 Vas well as access to V4+/V3+, Ti3+/Ti2+ and Fe2+/Fe+ couples. Separation of the V4+/V3+ and V3+/V2+ couples were found to be 2.0 V. Fe2(SO4)3 has both monoclinic and rhombohedral modifications that give a flat open-circuit voltage Voc = 3.6 V versus Li and a reversible capacity for ∼ 1.8 lithium atoms per formula unit. LixFe2(SO4)3 shows an abrupt voltage drop occurring for x > 2 that can be held in check by the addition of buffers such as Li3Fe2(PO4)3, FeV(SO4)3 and LiTi2(PO4)3. Changing the polyanion group from (SO4)2- to (PO4)3- in these framework compounds decreases the redox potentials from 3.2 to 2.5 V for the Ti4+/Ti3+ couple, 2.5 to 1.7 V for the V3+/V2+ couple and 3.6 to 2.8 V for the Fe3+/Fe2+ couple. Comparative advantages and disadvantages of framework cathodes for Li rechargeable battery applications are discussed.
UR - http://www.scopus.com/inward/record.url?scp=0030285942&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030285942&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0030285942
VL - 92
SP - 1
EP - 10
JO - Solid State Ionics
JF - Solid State Ionics
SN - 0167-2738
IS - 1-2
ER -