A three volt lithium ion battery with LiCoPO4 and zero-strain Li4Ti5O12 as insertion material

• LiCoPO4 was successfully synthesized via polymer network gel method.
• LiCoPO4/Li4Ti5O12 cells were successfully assembled.
• The reaction mechanism in the full cell LiCoPO4/Li4Ti5O12 is illustrated in detail.
• The effects of capacity matchup in LiCoPO4/Li4Ti5O12 cell were firstly studied.

A 3 V lithium ion battery with LiCoPO4 and zero-strain Li4Ti5O12 as insertion material is constructed and investigated. Electrochemical tests show that the full cell displays two operation voltage plateaus (3.24 V and 3.17 V). Further, the effects of the theoretical capacity matchup ratio between cathode and anode in the LiCoPO4/Li4Ti5O12 cell system on the electrochemical properties are firstly investigated. The LiCoPO4/Li4Ti5O12 cell delivers a highest initial discharge capacity of 135.6 mAh g−1. A 3.2 V lithium-ion battery would further extend the application of lithium ion batteries in energy conversion and storage applications.