title: Organic dicarboxylate negative electrode materials with remarkably small strain for high-voltage bipolar batteries.
abstract: As advanced negative electrodes for powerful and useful high-voltage bipolar batteries, an intercalated metal-organic framework (iMOF), 2,6-naphthalene dicarboxylate dilithium, is described which has an organic-inorganic layered structure of π-stacked naphthalene and tetrahedral LiO4 units. The material shows a reversible two-electron-transfer Li intercalation at a flat potential of 0.8 V with a small polarization. Detailed crystal structure analysis during Li intercalation shows the layered framework to be maintained and its volume change is only 0.33%. The material possesses two-dimensional pathways for efficient electron and Li(+) transport formed by Li-doped naphthalene packing and tetrahedral LiO3C network. A cell with a high potential operating LiNi(0.5)Mn(1.5)O4 spinel positive and the proposed negative electrodes exhibited favorable cycle performance (96% capacity retention after 100 cycles), high specific energy (300 Wh kg(-1)), and high specific power (5 kW kg(-1)). An 8 V bipolar cell was also constructed by connecting only two cells in series.
authors.affiliation: Toyota Central R&D Laboratories Inc. Nagakute, Aichi, 480-1192 (Japan). ogihara@mosk.tytlabs.co.jp.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ogihara
authors.forename: Tomomi
authors.initials: T
authors.lastname: Yasuda
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kishida
authors.forename: Tetsu
authors.initials: T
authors.lastname: Ohsuna
authors.forename: Kaito
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Nobuko
authors.initials: N
authors.lastname: Ohba
keywords: batteries; carboxylates; electrochemistry; intercalations; metal-organic frameworks