No abstract

A series of La-doped Li 3 V 2 (PO 4 ) 3 /C cathode materials for Li-ion batteries are synthesized by a sol-gelassisted, low-temperature sintering process. La(NO 3 ) 3 acts not only as the La source, but also, together with the intermediate product LiNO 3 , promotes combustion, the ultrahigh exothermic energy that is advantageous for the nucleation process. The subsequent sintering process at 600 C for 4 h is sufficient to produce highly crystalline La-doped Li 3 V 2 (PO 4 ) 3 /C composites. The as-prepared cathode materials display smaller particle size, lower electron-transfer resistance and faster Li ion migration, which is ascribed to enhanced Li-ion transfer because of the La doping. The resulting Li 3 V 1.96 La 0.04 (PO 4 ) 3 /C cathode has a stable specific capacity of 160 mA h g À1 at low charge-discharge rates over 100 cycles, and retained a stable capacity of up to 116 mA h g À1 at a rate of 5 C, which is 40% higher than the undoped pristine cathode.

The solubility data of lithium bis(oxalate)borate (LiBOB) were measured in six different solvents using the synthetic method and laser monitoring technique at temperatures ranging from (293.15 to 363.15) K under atmospheric pressure. The experimental solubilities of LiBOB in different solvents were correlated by the modified Apelblat equations. It is found the calculated solubility data show good consistency with the experimental values. On this basis, some thermodynamic parameters of LiBOB in different solvents, such as dissolution enthalpy, dissolution entropy, and dissolution Gibbs free energy, are also calculated. These results concerning the solubility of LiBOB in different solvents will provide fundamental data in the commercial application of LiBOB.