The electrochemical performances of nanoscale LiFePO4 and Li4Ti5O12 materials are described in this paper. The nanomaterials were synthesized by pyrolysis of an aerosol precursor. Both compositions required moderate heat-treatment to become electrochemically active. LiFePO4 nanoparticles were coated with a uniform, 2–4 nm thick carbon coating using an organic precursor in the heat-treatment step and showed a high tap density of 1.24g/cm3 despite the 50–100 nm particle size and 2.9 wt % carbon content. Li4Ti5O12 nanoparticles were between 50 and 200 nm and showed a tap density of 0.8g/cm3. The nanomaterials were tested both in half-cell configurations against Li metal and in LiFePO4/Li4Ti5O12 full cells. Nano-LiFePO4 showed a high discharge rate capability with values of 150 and 138 mAh/g at C/25 and 5C, respectively, after constant C/25 charges. Nano-Li4Ti5O12 also showed a high charge capability with values of 148 and 138 mAh/g at C/25 and 5C, respectively, after constant C/25 discharges; the discharge (lithiation) capability was comparatively slower. LiFePO4/Li4Ti5O12 full cells deliver charge/discharge capacity values of 150 and 122 mAh/g at C/5 and 5C, respectively.
BT - Journal of The Electrochemical Society C3 -doeff group
DA - 10/2009 DO - 10.1149/1.3223987 LA - eng M1 - 12 N2 -The electrochemical performances of nanoscale LiFePO4 and Li4Ti5O12 materials are described in this paper. The nanomaterials were synthesized by pyrolysis of an aerosol precursor. Both compositions required moderate heat-treatment to become electrochemically active. LiFePO4 nanoparticles were coated with a uniform, 2–4 nm thick carbon coating using an organic precursor in the heat-treatment step and showed a high tap density of 1.24g/cm3 despite the 50–100 nm particle size and 2.9 wt % carbon content. Li4Ti5O12 nanoparticles were between 50 and 200 nm and showed a tap density of 0.8g/cm3. The nanomaterials were tested both in half-cell configurations against Li metal and in LiFePO4/Li4Ti5O12 full cells. Nano-LiFePO4 showed a high discharge rate capability with values of 150 and 138 mAh/g at C/25 and 5C, respectively, after constant C/25 charges. Nano-Li4Ti5O12 also showed a high charge capability with values of 148 and 138 mAh/g at C/25 and 5C, respectively, after constant C/25 discharges; the discharge (lithiation) capability was comparatively slower. LiFePO4/Li4Ti5O12 full cells deliver charge/discharge capacity values of 150 and 122 mAh/g at C/5 and 5C, respectively.
PY - 2009 SP - A1041 EP - A1046 T2 - Journal of The Electrochemical Society TI - Nanoscale LiFePO4 and Li4Ti5O12 for high rate Li-ion batteries VL - 156 ER -