English
Inspired from century-old proven techniques in glass and steel-making, a paradigm shift in the way LFP/LMFP CAM are produced.
Recent history has shown that all processes once optimized can make a good LFP. The real challenge to meet the demand in the forthcoming decade lies in the cost (process and material) and the environmental impact, thus our choice: melt-synthesis.
The heat transfer and diffusion in a molten medium at around 1000°C is ideal to achieve fast reaction and allows the use of minimally processed reactants up to the mm size range while completing the reaction in less than 30 minutes.
With high reaction rates, thermodynamics are no longer theoretical boundaries, but define operating targets that can be used to achieve repeatable and predictable compositions. Thermodynamics also offers possibilities with respect to impurities management: controlled during melt or expelled from structure upon cooling.
The high reaction rate and thermodynamic conditions make it possible to consider a wide-range of reactants, thus making the melt process virtually limitless in the nature of the Li, Fe, P sources that can be used, allowing even combinations. Furthermore, LMFP is as easy to form as LFP. The same process is able to adapt rapidly to the whim of the market.
The synthesis, particle size reduction and coating steps occur sequentially. This provides an absolute freedom to adjust the process parameters in order to meet the customer specifications, all aspects of the process are decoupled. This segregation of the post-synthesis steps opens to door to an uncoated LFP/LMFP business model where OEMs could undertake their own proprietary fine sizing and coating steps.
The highly crystalline LFP obtained upon solidification makes the material very fragile and easy to grind. Size reduction down to < 0.1 µm-range requires less energy than is needed to jet mill Li2CO3 and FePO4 down to single digit µm.
The fast kinetic and thermodynamics allow for the use of less processed reactants (savings in waste, energy and water utilization). The melt-synthesis is capable of adjusting melt composition in-situ (within the synthesis vessel), reducing the risk of producing off-spec batches. The direct upgrading of process waste (off-spec finished CAM (humidity, particle size, BET), dust, magnetic rejects) without having to go through wet chemical recycling strategies improves yield and reduces the energy, water usage and waste generated.
Inventors of the melt-synthesis process for manufacturing LFP/LMFP