New high-voltage step at 4.8 V in cobalt free manganese based lithium phospho olivines for lithium-ion batteries

作者：Memm M^*; Koentje M; Axmann P; Wohlfahrt Mehrens M

来源：Journal of Power Sources, 2015, 276: 382-387.

DOI：10.1016/j.jpowsour.2014.09.065

• Materials science
• Lithium ion batteries
• Phospho olivine
• LiMnPO4

A new voltage step at 4.8 V can be activated in manganese based cobalt free phospho olivines by activating the utilisation of the Mn3+/4+ redox pair applying Mg2+ as a Li+-storage agent. CCCV cycling reveals a significant excess in discharge capacity of Mn Mg co-containing samples related to the theoretical single electron step of Mn2+/3+ and the occurrence of a new potential step at 4.8 V. These phenomena are not observed in Mg- or Mn-free samples even after charging them up to 5.3 V vs. Li/Li+. Similar observations are made for Ni Mn containing samples. Mg Mn containing cathode materials can be a first step towards cobalt free high voltage phosphates for Lithium Ion batteries.

• 出版日期2015-2-15