High-Throughput Solution Combustion Synthesis of High-Capacity LiFeBO₃Cathode

Aspiring for better cathodes beyond the LiFePO 4 system, recently LiFeBO 3 has been reported as a high-capacity (ca. 220 mAh/g) intercalation material involving the lowest reported volume change (ca. 2%) during its operation. It was obtained by conventional solid-state synthesis at 600°C for 12 h and careful cathode optimization. Pursuing an alternate energy-savvy synthetic route, here we report a high-throughput aqueous synthesis forming one-step carbon-coated nanoscale LiFe II BO 3 product, starting with the low-cost Fe III precursor. Known as solution combustion synthesis, this two-step synthetic method can yield the LiFe II BO 3 phase by a quick annealing at 400–600°C for just ≤1 minute. The resulting borate cathode delivers near 1-electron discharge capacity in excess of 170 mAh/g with excellent reversibility, the first such achievement using any solution based synthesis. Various synthesis aspects, physical and electrochemical properties of combustion prepared LiFe II BO 3 cathode have been presented, showcasing the versatility of this eco-efficient method to produce other metal borates and various polyanionic insertion materials for secondary batteries.