High-Performance CrO Cathode Materials with MnO as an Activator for High-Energy-Density Lithium Primary Batteries.

Chromium oxides (CrO) have attracted wide application due to their high theoretical capacity and high voltage for lithium primary batteries. However, CrO is usually prepared by pyrolysis of a CrO precursor and suffers from low capacity and poor rate capability due to the fusion of CrO during the high-temperature reaction process. Herein, MnO was investigated as an activator to study its impact on the electrochemical properties of CrO, which significantly changed with the addition of MnO during the calcination process. With the addition of MnO, the discharge capacity and rate capability of the reaction products (CrO-M) were dramatically improved compared with those of pure CrO. This improvement is attributed to the superior lithium-ion diffusion kinetics caused by the uniform surface structure and porous features, which reduce the charge transfer resistance. As a result, CrO-M10 exhibited an excellent discharge specific capacity of 388 mAh g at 0.1C with discharge voltage plateaus of about 3.0 V (vs Li/Li), reaching an energy density of 1223 Wh kg based on the cathode material. In addition, CrO-M showed remarkable rate performance, enabling a high-capacity retention of about 70% at 5C. Therefore, it is essential to add an activator agent during the preparation of CrO, which offers a promising avenue for the development of high-energy-density and high-rate-capability Li/CrO primary batteries.