摘要:
The electrochemical performance of rechargeable lithium battery cells comprising crystalline or amorphous FeIII iron phosphate active positive electrode compounds is improved by compound hydration and intimate ball-milled incorporation of electrically conductive carbon.
摘要:
The present invention relates to lithium secondary batteries and more specifically to positive electrode materials operating at potentials greater than 2.8 V vs. Li+/Li in nonaqueous electrochemical cells. In particular, the invention relates to crystalline nanometric carbon-free olivine-type LiFePO4 powders with enhanced electrochemical properties. A direct precipitation process is described for preparing crystalline LiFePO4powder, comprising the steps of: providing a water-based mixture having at a pH between 6 and 10, containing a water-miscible boiling point elevation additive, and Li(I), Fe(II) and P(V) as precursor components; heating said water-based mixture to a temperature less than or equal to its boiling point at atmospheric pressure, thereby precipitating crystalline LiFePO4 powder An extremely fine 50 to 200 nm particle size is obtained, with a narrow distribution. The fine particle size accounts for excellent high-drain properties without applying any carbon coating. This allows for a significant increase in the active material content of the electrode. The narrow distribution facilitates the electrode manufacturing process and ensures a homogeneous current distribution within the battery.
摘要翻译:本发明涉及锂二次电池,更具体地说涉及在非水电化学电池中工作电压大于2.8V的正极材料与Li + + / Li的关系。 特别地,本发明涉及具有增强的电化学性能的结晶纳米级无碳橄榄石型LiFePO 4 N 4 O 3粉末。 描述了用于制备结晶LiFePO 4粉末的直接沉淀方法,其包括以下步骤:提供pH6至10的含有水混溶沸点升高添加剂的水基混合物, 和作为前体成分的Li(I),Fe(II)和(V) 将所述水性混合物加热至大气压下的沸点以下,从而析出结晶LiFePO 4粉末,得到极细微的50〜200nm的粒径,分布窄。 在不施加任何碳涂层的情况下,细颗粒尺寸表现出优异的高排水性能。 这允许电极的活性物质含量显着增加。 窄的分布有助于电极制造过程,并确保电池内的均匀电流分布。
摘要:
The invention relates to materials for use as electrodes in an alkali-ion secondary (rechargeable) battery, particularly a lithium-ion battery. The invention provides transition-metal compounds having the ordered-olivine, a modified olivine, or the rhombohedral NASICON structure and the polyanion (PO4)3− as at least one constituent for use as electrode material for alkali-ion rechargeable batteries.
摘要翻译:本发明涉及用作碱离子二次(可再充电)电池,特别是锂离子电池中的电极的材料。 本发明提供了具有有序橄榄石,改性橄榄石或菱方NASICON结构的过渡金属化合物和作为至少一种成分的聚阴离子(PO 3 SO 3)3 - 用作碱电池可充电电池的电极材料。
摘要:
The present invention relates to lithium secondary batteries and more specifically to positive electrode materials operating at potentials greater than 2.8 V vs. Li+/Li in nonaqueous electrochemical cells. In particular, the invention relates to crystalline nanometric carbon-free olivine-type LiFePO4 powders with enhanced electrochemical properties. A direct precipitation process is described for preparing crystalline LiFePO4powder, comprising the steps of: —providing a water-based mixture having at a pH between 6 and 10, containing a water-miscible boiling point elevation additive, and Li(I), Fe(II) and P(V) as precursor components; —heating said water-based mixture to a temperature less than or equal to its boiling point at atmospheric pressure, thereby precipitating crystalline LiFePO4 powder. An extremely fine 50 to 200 nm particle size is obtained, with a narrow distribution. The fine particle size accounts for excellent high-drain properties without applying any carbon coating. This allows for a significant increase in the active material content of the electrode. The narrow distribution facilitates the electrode manufacturing process and ensures a homogeneous current distribution within the battery.
摘要:
The invention relates to active materials for the manufacture of Li-based batteries. A crystalline nanometric powdered material with formula Lix(M, M′)PO4, in particular LixFePO4 (O≦x≦1), is disclosed, exhibiting single phase Li insertion/extraction mechanism at room temperature when used as positive electrode material in Li-based batteries. Compared to current LiFePO4, the novel material results in smooth, sloping charge/discharge voltage curve greatly simplifying the monitoring of the state of charge of the batteries. The coexistence of mixed valence states for Fe (i.e. FeIIIVFeII) is believed to increase the electronic conductivity in the room temperature single phase LixFePO4 material, compared to state of the art two-phase materials. This, together with the nanometric size of the particles and their sharp monomodal size distribution, contributes to the exceptional high-rate capability demonstrated in batteries.
摘要:
The invention provides a new route for the synthesis of carbon-coated powders having the olivine or NASICON structure, which form promising classes of active products for the manufacture of rechargeable lithium batteries. Carbon-coating of the powder particles is necessary to achieve good performances because of the rather poor electronic conductivity of said structures. For the preparation of coated LiFePO4, sources of Li, Fe and phosphate are dissolved in an aqueous solution together with a polycarboxylic acid and a polyhydric alcohol. Upon water evaporation, polyesterification occurs while a mixed precipitate is formed containing Li, Fe and phosphate. The resin-encapsulated mixture is then heat treated at 700° C. in a reducing atmosphere. This results in the production of a fine powder consisting of an olivine LiFePO4 phase, coated with conductive carbon. When this powder is used as active material in a lithium insertion-type electrode, fast charge and discharge rates are obtained at room temperature and an excellent capacity retention is observed.
摘要:
Methods of manufacture and use of phosphates of transition metals are described as positive electrodes for secondary lithium batteries, including a process for the production of LiMPO4 with controlled size and morphology, M being FexCoyNizMnw, where 0≦x≦1,0≦y≦1, 0≦w≦1, and x+y+z+w=1. According to an exemplary embodiment, a process is described for the manufacture of LiFePO4 including the steps of providing an equimolar aqueous solution of Li1+, Fe3+ and PO43−, evaporating water from the solution to produce a solid mixture, decomposing the solid mixture at a temperature of below 500° C. to form a pure homogeneous Li and Fe phosphate precursor, and annealing the precursor at a temperature of less than 800° C. in a reducing atmosphere to produce the LiFePO4 powder. The obtained powders can have a particle size of less than 1 μm, and can provide superior electrochemical performance when mixed for an appropriate time with an electrically conductive powder.
摘要翻译:过渡金属的磷酸盐的制造和使用方法被描述为二次锂电池的正电极,包括用于制备具有受控尺寸和形态的LiMPO 4的方法,M是Fe x x 其中0 <= x <= 1,0 <= y <= 1,0
摘要:
The invention relates to materials for use as electrodes in an alkali-ion secondary (rechargeable) battery, particularly a lithium-ion battery. The invention provides transition-metal compounds having the ordered-olivine, a modified olivine, or the rhombohedral NASICON structure and the polyanion (PO4)3− as at least one constituent for use as electrode material for alkali-ion rechargeable batteries.
摘要:
The invention relates to crystalline nanometric olivine-type LiFe1-xMxPO4 powder with M being Co and/or Mn, and 0≦x≦1, with small particle size and narrow particle size distribution. A direct precipitation process is described, comprising the steps of: providing a water-based mixture having at a pH between 6 and 10, containing a dipolar aprotic additive, and Li(I), Fe(II), P(V), and Co(II) and/or Mn(II) as precursor components; heating said water-based mixture to a temperature less than or equal to its boiling point at atmospheric pressure, thereby precipitating crystalline LiFe1-xMxPO4 powder. An extremely fine particle size is obtained of about 80 nm for Mn and 275 nm for Co, both with a narrow distribution.