Electrode material with thermosensitive properties, and preparation method thereof

Abstract

The invention belongs to the technical field of lithium ion batteries, and particularly relates to an electrode material with thermosensitive properties, and a preparation method thereof. The electrode material comprises a core formed by a lithium metal oxide, and a shell formed by a thiophene derivative, wherein the weight of the thiophene derivative accounts for 0.1-8% of the total weight of the electrode material, and the Curie temperature of the thiophene derivative is 90-130 DEG C. Compared with the prior art, the electrode material with the core-shell structure, which is formed in a manner that the lithium metal oxide is coated with the thiophene derivative, has the advantages that the thermosensitive properties are excellent, that is, each active particle has the positive temperature coefficient characteristic; and when the internal temperature of a battery adopting the electrode material rises up to the Curie temperature of the material, the resistance of the electrode material can be sharply increased, so that a conductive network among the electrode material particles is blocked, the electron transfer speed is greatly reduced, the battery can be effectively prevented from further temperature rises, and the battery safety is further improved.

Description

technical field

[0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an electrode material with thermosensitive properties and a preparation method thereof. Background technique

[0002] Although lithium-ion batteries have been widely used in daily life, their safety issues have always attracted much attention, which is also an urgent bottleneck to be solved when they are widely used in power batteries. Because lithium-ion batteries are composed of electrodes with high reactivity and flammable organic electrolytes, this leads to great congenital defects in the safety performance of lithium-ion batteries. Under abuse conditions, lithium-ion batteries may generate a large amount of heat, causing the internal temperature of the battery to rise sharply, resulting in thermal runaway, which can lead to serious accidents such as fire or explosion.

[0003] Generally speaking, the thermal stability of the battery is a key factor...

Examples

Embodiment 1

[0030] Weigh LiNi according to the weight ratio of 92:8 1 / 3 co 1 / 3 mn 1 / 3 o 2 and poly-3-hexylthiophene powder, dissolve the poly-3-hexylthiophene powder in chloroform, then slowly add LiNi 1 / 3 co 1 / 3 mn 1 / 3 o 2 , fully stirred at a speed of 2000r / min to obtain a uniform dispersion; the dispersion was dried at 130°C for 4 hours, so that poly-3-hexylthiophene was uniformly coated on LiNi 1 / 3 co 1 / 3 mn 1 / 3 o 2 surface, that is, to obtain the above-mentioned positive electrode material with heat-sensitive properties; the Curie temperature of the positive electrode material obtained by this preparation method is 130°C.

Embodiment 2

[0032] Weigh LiNi according to the weight ratio of 95:5 1 / 3 co 1 / 3 al 1 / 3 o 2 and poly-3-heptylthiophene powder, the poly-3-heptylthiophene powder was dissolved in THF, then slowly added LiNi 1 / 3 co 1 / 3 al 1 / 3 o 2 , fully stirred at a speed of 2500r / min to obtain a uniform dispersion; the dispersion was dried at 150°C for 3 hours, so that poly-3-heptylthiophene was uniformly coated on LiNi 1 / 3 co 1 / 3 al 1 / 3 o 2 Surface, that is, to obtain the above-mentioned positive electrode material with heat-sensitive properties; the Curie temperature of the positive electrode material obtained by this preparation method is 125°C.

Embodiment 3

[0034] Weigh LiCoO according to the weight ratio of 99:1 2 and poly-3-octylthiophene powder, the poly-3-octylthiophene powder was dissolved in N-methylpyrrolidone, and then slowly added LiCoO 2 , fully stirred at a speed of 3000r / min to obtain a uniform dispersion; the dispersion was dried at 160°C for 2 hours, so that poly-3-octylthiophene was uniformly coated on LiCoO 2 surface, that is, to obtain the above-mentioned positive electrode material with heat-sensitive properties; the Curie temperature of the positive electrode material obtained by this preparation method is 120°C.

technical field

[0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an electrode material with thermosensitive properties and a preparation method thereof. Background technique

[0002] Although lithium-ion batteries have been widely used in daily life, their safety issues have always attracted much attention, which is also an urgent bottleneck to be solved when they are widely used in power batteries. Because lithium-ion batteries are composed of electrodes with high reactivity and flammable organic electrolytes, this leads to great congenital defects in the safety performance of lithium-ion batteries. Under abuse conditions, lithium-ion batteries may generate a large amount of heat, causing the internal temperature of the battery to rise sharply, resulting in thermal runaway, which can lead to serious accidents such as fire or explosion.

[0003] Generally speaking, the thermal stability of the battery is a key factor...

Examples

Embodiment 1

[0030] Weigh LiNi according to the weight ratio of 92:8 1 / 3 co 1 / 3 mn 1 / 3 o 2 and poly-3-hexylthiophene powder, dissolve the poly-3-hexylthiophene powder in chloroform, then slowly add LiNi 1 / 3 co 1 / 3 mn 1 / 3 o 2 , fully stirred at a speed of 2000r / min to obtain a uniform dispersion; the dispersion was dried at 130°C for 4 hours, so that poly-3-hexylthiophene was uniformly coated on LiNi 1 / 3 co 1 / 3 mn 1 / 3 o 2 surface, that is, to obtain the above-mentioned positive electrode material with heat-sensitive properties; the Curie temperature of the positive electrode material obtained by this preparation method is 130°C.

Embodiment 2

[0032] Weigh LiNi according to the weight ratio of 95:5 1 / 3 co 1 / 3 al 1 / 3 o 2 and poly-3-heptylthiophene powder, the poly-3-heptylthiophene powder was dissolved in THF, then slowly added LiNi 1 / 3 co 1 / 3 al 1 / 3 o 2 , fully stirred at a speed of 2500r / min to obtain a uniform dispersion; the dispersion was dried at 150°C for 3 hours, so that poly-3-heptylthiophene was uniformly coated on LiNi 1 / 3 co 1 / 3 al 1 / 3 o 2 Surface, that is, to obtain the above-mentioned positive electrode material with heat-sensitive properties; the Curie temperature of the positive electrode material obtained by this preparation method is 125°C.

Embodiment 3

[0034] Weigh LiCoO according to the weight ratio of 99:1 2 and poly-3-octylthiophene powder, the poly-3-octylthiophene powder was dissolved in N-methylpyrrolidone, and then slowly added LiCoO 2 , fully stirred at a speed of 3000r / min to obtain a uniform dispersion; the dispersion was dried at 160°C for 2 hours, so that poly-3-octylthiophene was uniformly coated on LiCoO 2 surface, that is, to obtain the above-mentioned positive electrode material with heat-sensitive properties; the Curie temperature of the positive electrode material obtained by this preparation method is 120°C.