More than just a protection layer: Inducing chemical interaction between Li3BO3 and LiNi0·5Mn1·5O4 to achieve stable high-rate cycling cathode materials

Simultaneous Near‐Surface Trace Doping and Surface Modifications by Gas–Solid Reactions during One‐Pot Synthesis Enable Stable High‐Voltage Performance of LiCoO2

“…[9] Coating spinel LiCo x Mn 2x O 4 shells on the layered LCO with a nonco herent relationship through posttreatments was reported to enhance its cyclability and rate capability for the upper cutoff voltage of 4.5 V. [10] Thus, the coherent coating of spinel shells is expected to exhibit better longterm stability at high voltages as a result of the perfect lattice match between the coherent spinel shell and the layered structure. Its combination with fast Liion conductors such as Li 3 BO 3 , [11] Li 2 SiO 3 , [12] Li 2 SO 4 , [13] and Li 3 PO 4 , [14] would not only prevent the direct contact between active materials and electrolytes but also increase the Liion conductivity. Therefore, coating fast Liion conductors on LiCoO 2 may be an effective strategy for the improvement of cycling performance at high voltages.LiCoO 2 (LCO) with a high theoretical capacity of 274 mAh g -1 can rarely achieve a high practical capacity even at an upper cutoff voltage of 4.6 V due to severe structural instability and interface side reactions.…”

Enhancing the High-Voltage Cycling Performance and Rate Capability of LiNi0.8Co0.1Mn0.1O2 Cathode Material by Codoping with Na and Br

“…Moreover, the peak at 641.9 eV corresponds to MnBr 2 , as shown in the Mn 2p of the NCM-NB2 in Figure c . The O 1s peaks at 531.4 and 529.3 eV (Figure d) belong to lithium impurities and lattice oxygen bonds, respectively . The peak at 289.8 eV in the C 1s spectrum (Figure e) can be specified as Li 2 CO 3 , while the peak at 284.8 eV corresponds to hydrocarbons .…”

“…39 The O 1s peaks at 531.4 and 529.3 eV (Figure 3d) belong to lithium impurities and lattice oxygen bonds, respectively. 40 The peak at 289.8 eV in the C 1s spectrum (Figure 3e) can be specified as Li 2 CO 3 , while the peak at 284.8 eV corresponds to hydrocarbons. 41 In Figure S3a, the Na 1s binding energy measured in NCM-NB2 is ∼1 072 eV, which is consistent with the binding energy of sodium oxide; therefore, this result indicates that the valence state of Na in the doped material is +1.…”

Insights for the New Function of N,N-Dimethylpyrrolidone in Preparation of a High-Voltage Spinel LiNi0.5Mn1.5O4 Cathode

“…Lithium ion batteries (LIBs) have been an important part of portable electronic products and electric vehicles since they were commercialized in early 1990s. − However, the dissatisfactory energy density has been the main challenge for its further applications . Cathodes, vital components of LIBs, play a major role in defining their voltage and energy density .…”

“…Cathodes, vital components of LIBs, play a major role in defining their voltage and energy density . Spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) has drawn particular attention among various cathode materials owing to its high charge–discharge capacity and superior energy density, which are the two key requirements for LIBs. ,− However, the poor electronic conductivity and poor cycling stability have been the principal obstacles for its commercialization.…”