K. Sumiya et al., Enhancement of the electrochemical Li doping/undoping reaction rate of a graphitic material by an evaporated film of Sn, Zn or Pb, J ELEC CHEM, 462(2), 1999, pp. 150-156
For the purpose of obtaining an improved performance of the carbon anode ma
terial for Li-ion secondary batteries a surface modification by metal evapo
ration onto the carbon surface has been examined. When a film of Pb, Sn or
Zn was evaporated onto the surface of a graphitic carbon fiber in vacuo it
exhibited markedly higher cyclic voltammogram peaks due to Li doping/undopi
ng as compared to those of an untreated one. This indicates that the electr
ochemical reactions are enhanced by the treatment. With a simple treatment,
Zn gave rise to a good cycleability. However, with a sample covered with a
him of Pb or Sn, the enhanced peak current due to the deintercalation of L
i was decreased successively upon repetition of the doping/undoping cycling
. The gradual deterioration of the Sn deposited carbon could be suppressed
by making the deposited Sn film amorphous. (C) 1999 Elsevier Science S.A. A
ll rights reserved.