Sustainable, heat-resistant and flame-retardant cellulose-based composite separator for high-performance lithium ion battery

Sustainable, hot
Flame-resistant-
Flame retardant cellulose
The base composite non-woven fabric was successfully prepared and its potential application in high efficiency separator was explored.
Performance lithium ion battery.
Prove this flame.
Flame retardant cellulose
The base composite separator has good flame retardant performance, excellent heat resistance and appropriate mechanical strength.
Compared with commercial polypropylene (PP)
This composite separator has better electrolyte absorption, better interface stability and enhanced ion conductivity.
In addition, lithium cobalt oxide (LiCoO2)
The/graphite battery using this composite separator, thanks to its simple ion transfer and excellent interface compatibility, exhibits better rate capability and cycle retention capability than the PP separator.
In addition, lithium iron phosphate (LiFePO4)
The/lithium battery with this composite Separator provides stable cycle performance and thermal dimensional stability even at a high temperature of 120 °c.
All of these fascinating features will promote this composite separator in high
Performance lithium ion battery. PP separator (Celgard 2500)
Purchased from Celgard for comparative analysis (USA).
Shandong Yinying Chemical Co. , Ltd. supplies cellulose pulp. , Ltd (China). Nitrogen-
Phosphorus composite flame retardant (FR)
Purchase from Qingdao Haihua flame-
Flame retardant materials company, Ltd. (Shandong, China).
Sodium algae (SA)
Provided by Qingdao Mingyue company (Shandong, China).
Silica Nanoparticles (30u2005nm)
Supply of Guangcheng chemical reagent Co. , Ltd. (Tianjin, China).
Other chemical reagents are purchased commercially and can be used without further purification.
Valley machine (ZDJ100)
Provided by Shandong Yinying Chemical Co. , Ltd. , Ltd (China).
The paper machine was purchased from Estanit GbmH. , Ltd. (German).
Observe the morphology of the separator using field emission scanning electron microscopy (Hitachi S-4800 at 3u2005kV).
Measure the thickness of each separator using a millimetre.
The air penetration rate is using Gley-
Type electric instrument (4110N, Gurley)
By measuring the time the air passes through the separator at 100 kbps cc.
By immersing the separator in n-
Ethanol of 2 Thanh, calculated with the following equation: equation(1): P = [(m/ρ)/(m/ρ + m/ρ)]
X 100%, where m and m are the mass of the separator, n-
Density and n-of isolates-
Ethanol, respectively.
Liquid electrolyte absorption is determined by the following equation. (2): EU = [(W − W)/W]
X 100%, where W and W represent the weight of the separator before and after the absorption of the liquid electrolyte, respectively.
Additional solutions (n-
Secondary or electrolyte)
On the surface of the separator, absorb with the filter paper before measuring the weight.
Contact angle measurement using jc2000 c contact angle meter.
The contact angle of 5 μ l electrolyte droplets was measured using the jc2000 c contact angle meter.
The tortuosity of the membrane is calculated by using the following relationship:, where, the conductivity of pure liquid electrolyte and electrolyte-
Soak the film separately, and P is the hole rate of the film. The stress-
Using Instron-test the strain curve of the separator
33 million tensile testing machine (USA)
Samples with a width of 1 cm and a length of 8 cm are used at a speed of 10mm min.
Young\'s modulus (E)
The following equation can be used to calculate: Eq. (3)
: E = σ/E, where the σ and E stresses and strain of the separator.
Differential Scanning Heat Meter (
PerkinElmer Diamond DSC)
Used to evaluate the thermal performance of the separator.
Samples were scanned at a heating rate of 10 °c/min in N atmosphere from 50 °c to 300 °c.
To evaluate its heat shrinkage behavior, place the separator in the oven and heat 0 at 150 °c. 5u2005h.
Temperature shrinkage ratio (TSR)
Calculated based on Eq. (4): TSR (%)= (S − S/S)× 100%.
Here, S and S represent the area of the separator before and after heat treatment at a series of temperatures of 0.
5 u2005 h respectively.
The contact test between the hot iron tip and the separator is as follows: first heat the soldering iron tip to 400 °c, gently contact the separator for 1 second, and then record the change of the surface shape of the separator.
Limit oxygen index (LOI)
Measurement is using JF-
Type 3 Oxygen Index tester (China).
Determination of heat release value by automatic oxygen bomb Heat Meter (
IKA C200, Germany).
The separator for the measurement of the electrical stability is sandwiched between the lithium metal and the stainless steel electrode in the test battery.
Then, in the case of a scan rate of 1, the electro-chemical stability was measured using a linear scanning kVA. 0u2005mV s from 2. 5u2005V to 6u2005V.
Ion conductivity and battery resistance were evaluated by AC impedance analysis (Zennium)
In the frequency range from 1 hz to 10 hz, at the AC voltage of 10 mv.
The ion conductivity is then calculated using the formula: σ = L/RA, where L is the thickness of the separator, A is the contact area between the separator and the stainless steel electrode, and R is the main resistance.
Full currency (2032-type)
With the LiCoO cathode, the graphite anode and separator soaked with liquid electrolyte are assembled in ar-
Box full of gloves
The anode consists of 93% graphite, 2% % carbon black and 1. 5 rwWt % CMC and 3.
Ding benzene of 5wt wt % is used as a polymer adhesive.
The cathode is composed of 90 wt % LiCoO, carbon black of 5 wt % and Poly disodium of 5 PTFE wt %.
The electrolyte is LiPF (1u2005M)
Ethylene carbonate (EC)
/Carbonated Asian roots (DMC)(1:1 v/v).
Rate Capability and cycle stability using a land battery test system.
The current density of charge/discharge is from 0. 2u2005C (20u2005mA g)to 8. 0u2005C (800u2005mA g)
For the rate capability within the voltage range between 2. 75u2005V and 4. 2u2005V.
The battery cycles at a fixed charge/discharge current density of 0. 5u2005C (50u2005mA g)/0. 5u2005C (50u2005mA g). A coil cell (2032-type)
Assemble by clamping a separator between the lithium metal foil anode and the lifpo cathode and then filling the liquid electrolyte.
The Lifpo cathode is composed of carbon black of 90 wt % lifpo, 10 wt % and Poly disodium of 5 PVC wt %.
The electrolyte is lithium two (oxalate)borate LiBOB (1u2005M)
With propylene carbonate (PC).
At a high temperature of 120 °c, a land battery test system is used to characterize the cycle stability of the battery
The battery cycles at a fixed charge/discharge current density of 0. 5u2005C/0.
Within the voltage range between 2 5 u2005 c. 5u2005V and 4. 0u2005V.