Some aspects of the present disclosure relate to systems and processes for the conversion of lithium phosphate into a low-phosphate solution containing lithium which may be suitable as feedstock for the production of saleable lithium products.

Embodiments described herein relate to recycling of spent lithium battery material. In some aspects, a method can include suspending a lithium source in a solvent containing an oxidation reagent to extract lithium, forming an extracted lithium solution, separating the extracted lithium solution from residual solids of a lithium source, purifying the extracted lithium solution by precipitating and filtering impurities, and precipitating the lithium in the purified lithium solution to generate lithium carbonate (Li.sub.2CO.sub.3). In some embodiments, the method can further include preprocessing the lithium source to improve kinetics of the lithium extraction. In some embodiments, the preprocessing can include a cutting or shredding step to downsize the lithium source. In some embodiments, the lithium source can include lithium-ion battery waste. In some embodiments, the oxidation reagent can include sodium persulfate (Na.sub.2S.sub.2O.sub.8), potassium persulfate (K.sub.2S.sub.2O.sub.8), ammonium persulfate (NH.sub.4).sub.2S.sub.2O.sub.8, hydrogen peroxide (H.sub.2O.sub.2), ozone (O.sub.3), and/or nitrous oxide (N.sub.2O).

A system and method combine a first reactant with a second reactant to create a reaction product. A first pump is in fluid communication with a reaction vessel and a source of the first reactant. A second pump is in fluid communication with the reaction vessel and a source of the second reactant. A gas sparger is located in the reaction vessel, and the gas sparger is in fluid communication with a gas source for providing gas to the reaction vessel. A controller is configured to execute a program stored in the controller to: (i) receive a sensor signal based on a force exerted by the reaction vessel in a direction toward the sensor, and (ii) operate the first pump and the second pump to deliver to the reaction vessel the first reactant and the second reactant thereby causing a reaction that creates the reaction product.

A preparation method of CsDFP for aqueous negative electrode slurry includes carrying out ion exchange reactions with LiPO.sub.2F.sub.2 and a cesium source. The activation energy of Li.sup.+ intercalation in the negative electrode is reduced due to the existence of Cs.sup.+, leading to a better rate performance. Further, the impedance growth rate of the batteries is reduced and the high temperature storage performance is excellent since PO.sub.2F.sub.2 participates in the electrochemical reaction to form a stable low-impedance SEI film on the surface of the negative electrode plate. Moreover, films are continuously formed to repair the SEI films under the gradual release of CsDFP, which is conducive to inhibiting the growth of lithium dendrites during long-term high-rate cycling, thereby obtaining an improved cycle performance.