Lithium Isotope Effect Accompanying Chemical Insertion of Lithium into Graphite

Abstract

Lithiumwaschemicallyintercalated from 1-methoxybutane solutionoflithiumand naphthalene intog raphiteand viceversa ,a nd lithiumi sotope fractionationaccompanyingthosei ntercalation and deintercalationp rocessesw asobserved.6 Liwasalways preferentiallyfractionated intothe graphitep hase. The single-stage lithiumi sotope separationf actoru pon intercalationwasabout 1.023 at25 C, nearlyindependentof the structureofthe lithium-graphiteintercalationcompounds formed. Amuchsmallerseparationfactorwasobserved forthe deintercalationprocess,suggesting the existenceo fl ithiumsites(surfaceareas)o thert hanthe sitesbetween graphene layers of the host graphite. Separationf actordatawereconsistentw iththe followingd ecreasingo rderof the 6 Li-to-7 Lireduced partitionf unctionratio (RPFR):R PFR of 1-methoxybutane solution>RPFR of surfaceareas>RPFR of metallithium>RPFR of graphene interlayersites.

Observation of Lithium Isotope Effects Accompanying Electrochemical Release from Lithium Cobalt Oxide

“…The S value was estimated to be 1.045 to 1.060, which suggests that rather large lithium isotope effects are realized upon charge reaction at the interface of the LiCoO 2 cathode and the 1 M LiClO 4 /EC/MEC electrolyte solution. The estimated S value of 1.045 to 1.060 is quite large compared to those observed for the charge reaction at the electrolyte/anode interfaces with a maximum value of 1.027 at 25 • C [2] and comparable to those reported for the amalgam method [12,13].…”

Lithium Isotope Effect Accompanying Electrochemical Intercalation of Lithium into Graphite

“…MO calculations on lithium species modeling those in the EC/MEC electrolyte and Li-GICs are in progress, and part of calculations has already been published [17]. In a previous paper on chemical insertion of lithium into graphite [20], it was observed that S is independent of m in Li m C between 0.065 and 0.17. The present results show that S is shallowly dependent on m in the range m = 0.032 to 0.14.…”

Lithium Isotope Effects upon Electrochemical Release from Lithium Manganese Oxide

“…We have been investigating the method of lithium isotope separation based on lithium isotope effects accompanying electrode reactions of lithium ion secondary batteries [1][2][3][4][5][6][7][8]. These reactions may be categorized into two classes, i. e., the charge and discharge reactions.…”