Lecture 5 1956 Cathode material for LIBs: Li-Mn-O and NCM Chen Junsong School of Materials and Energy 2020.04
Cathode material for LIBs: Li-Mn-O and NCM Chen Junsong School of Materials and Energy 2020.04 Lecture 5
Content /986 ·Introduction 00 Chemistry Molecular structure and Li diffusion Advantages and disadvantages 2
Content • Introduction • Chemistry • Molecular structure and Li diffusion • Advantages and disadvantages 2
Phase diagram of Li-Mn-O /986 Mn Multiple compositions Due to different oxidation states of Mn Il-VII Most important states Il,IV,VIl MnO LiMngO Most stable state ll MnO LizMn,O LiMnO2☑ λ-MnO2 LiMn,On2 λ-MnO2 Li,O LiMn204 4V Solid State lonics,69(1994)59 LiMnO2 3V Li2Mn4O9 LizMns1 LiMngO12 LisMn409 3V Li2MnO3∠天Li6.5Mn5O12 3
Phase diagram of Li-Mn-O • Multiple compositions • Due to different oxidation states of Mn II-VII • Most important states II, IV, VII • Most stable state II Solid State Ionics, 69 (1994) 59 3
Types of Li-Mn-O /986 ·LiMn2O4 。Spinel structure LiMnO2 Layered structure,like LiCoO, 4
Types of Li-Mn-O • LiMn2O4 • Spinel structure • LiMnO2 • Layered structure, like LiCoO2 4
Comparison of cathode materials Composition LiFePOa LiMn2O LiMnO2 LiCoO2 LiNiOz LiNiCo,Mn,O2 Crystal Olivine Spinel Layered structure Layered Theoretical C.(mAh/g) 170 148 286 274 274 278 True C. 130-140 100-120 200 135-140 190-210 155-165 (mAh/g) Voltage(V) 3.2-3.7 3.8-3.9 3.4-4.3 3.6 2.5-4.1 3.0-4.5 Cycle life >2000 >500 Poor >300 Poor >800 Abundance Great Good Good Poor Good Poor of metal Toxicity None None None Co Ni Co/Ni Safety Great Good Good Poor Poor Moderate Operating >50 Temp.(℃) -20~75 fading Unstable -20~55 N/A -20~55 fast at high T 5
Comparison of cathode materials Composition LiFePO4 LiMn2O4 LiMnO2 LiCoO2 LiNiO2 LiNixCoyMnzO2 Crystal structure Olivine Spinel Layered Layered Theoretical C. (mAh/g) 170 148 286 274 274 278 True C. (mAh/g) 130-140 100-120 200 135-140 190-210 155-165 Voltage (V) 3.2-3.7 3.8-3.9 3.4-4.3 3.6 2.5-4.1 3.0-4.5 Cycle life ＞2000 ＞500 Poor ＞300 Poor ＞800 Abundance of metal Great Good Good Poor Good Poor Toxicity None None None Co Ni Co/Ni Safety Great Good Good Poor Poor Moderate Operating Temp. (℃) -20～75 ＞ 50 fading fast Unstable at high T -20 ～55 N/A -20 ～55 5