A5064636842- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advanced Battery Technologies Research
- Extraction and Separation Processes
- Supercapacitor Materials and Fabrication
- Electrical and Thermal Properties of Materials
- Ferroelectric and Piezoelectric Materials
- Electrocatalysts for Energy Conversion
- Graphene research and applications
- Electronic Packaging and Soldering Technologies
- Advanced battery technologies research
- Fuel Cells and Related Materials
Dalhousie University
2019-2024
Surface reactions between Ni-rich cathode materials and electrolytes limit the achievable specific capacity lifetime in high energy density Li-ion batteries based on these materials. A core–shell approach, which contains a less reactive shell-phase top of high-capacity core-phase, can be used to reduce surface reactions. However, interdiffusion elements core shell phases occur during calcination, limits choice phase temperature window synthesis, often increases minimum thickness. Tungsten...
With the growing number of academic researchers focused on lithium-ion batteries, cell format choice is often overlooked. Coin cells that utilize either a lithium metal or greatly oversized graphite negative electrode are common but can provide unrealistic testing results when compared to commercial pouch-type cells. Instead, single-layer pouch more similar those used in industry while not requiring large amounts active material. Moreover, their assembly process allows for better...
The volumetric capacity of typical Na-ion battery (NIB) negative electrodes like hard carbon is limited to less than 450 mAh cm −3 . Alloy-based such as phosphorus (P), tin (Sn), and lead (Pb) more double the carbon, all having a theoretical above 1,000 in fully sodiated state. These alloy materials have massive volume expansion, with P expanding by almost 300% both Sn Pb about 400% their initial volumes when sodiated. This work shows that despite this large change, excellent half-cell...
Cobalt-free, single crystal layered-oxide positive electrode materials like Li 1+x [Ni 0.6 Mn 0.4 ] 1−x O 2 (NM64) have received recent interest because of their low cost, high-voltage stability, and good cycle life. In this work, NM64 is successfully produced with a simple all-dry synthesis process that requires no water, intermediate chemicals, produces little waste. The synthesized has ≤ 4% nickel in the lithium layer based on Rietveld refinement powder XRD patterns, median particle size...
Nickel-rich layered positive electrode materials are normally made by a “co-precipitation-sintering” method. Mixed transition metal hydroxides called “precursors” prepared co-precipitation to ensure homogeneous cation mixing at the atomic level and create spherical particles which high-performance poly-crystalline materials. Single crystal materials, show better capacity retention in long-term cycling can be from same mixed hydroxide precursors sintering higher temperature inevitably...
Surface modification has been shown to be useful for improving the cycling performance of cathode materials. Typically hetero-compositional coatings are applied on particle surfaces using methods, such as aqueous deposition and atomic layer (ALD), that can expensive inefficient. In this report, a dry mechanofusion method was used treat particles with no auxiliary coating applied. This resulted in drastic reduction surface area elimination features particles. Furthermore, processing results...
Uniform ∼10-μm particles are important in several applications, including the metal oxide and graphite active materials Li-ion batteries. Current production methods (e.g., co-precipitation spheronization) can be wasteful have limited composition scope. Here, we report dry particle microgranulation (DPMG) as a method for synthesizing highly engineered by consolidating fine, even submicron into that tens of microns. DPMG enables precise control internal variation, shape, morphology is not...
Physical mixtures of LiMn 2 O 4 (LMO) and NMC active cathode materials is a well-known strategy in commercial batteries to achieve better cycling storage performance than cells with pure LMO cathode. In this work, we demonstrated similar synergic effect LiFePO (LFP)/NMC640 material blends. Blending LFP NMC640 the weight ratio 90% 10% lead improvements compared alone. A clear linear coordination between capacity loss iron deposition on graphite anode was observed these blended cells. This...
This work involves improving the lifetime of lithium-ion cells during high voltage cycling using electrolyte additives. Three generations additives were investigated and screened in NMC442/graphite pouch a 24 h voltage-hold protocol at 40 °C to accelerate oxidative reactions occurring 4.4 V. Once promising combinations identified, they then tested cobalt-free NMC640/graphite for long-term upper cutoff voltages 4.3, 4.4, 4.5 V temperatures 20, 40, 55 °C. Degradation mechanisms probed dV/dQ...
Abstract Sodium-ion batteries (NIBs) are of growing interest due to their expected lower cost than many lithium-ion (LIBs). However, most NIBs suffer from volumetric energy density LIBs. Lead (Pb) can replace hard carbon in the NIB negative electrode substantially increase its and has been shown have no capacity fade over hundreds cycles half cells. Pb also experiences 387% volume expansion upon full sodiation, which presumably leads significant changes morphology. In this work, morphology...
Abstract Polyethylene terephthalate (PET) tape is widely used by well-known lithium-ion battery manufacturers to prevent electrode stacks from unwinding during assembly. PET selected since it has suitable mechanical and electrical properties, but its chemical stability been largely overlooked. In the absence of effective electrolyte additives, can depolymerize into monomer dimethyl (DMT), which an unwanted redox shuttle that induces significant self-discharge in a cell. This study presents...
Abstract One of the biggest issues facing electric vehicles with LiFePO4 (LFP) batteries is state charge management. Over much window, voltage both LFP and LiMnxFe1-xPO4 (LMFP) does not vary. Therefore, management for relies on coulomb counting, which requires frequent charging to 100% remain accurate. We propose use signal from pressure sensors placed between prismatic cells in battery modules help determine LMFP batteries. Using pouch demonstrate this principle, vs. time profiles...
Every lithium-ion battery cell produced today that is either wound or stacked contains tape. This tape serves the mechanical purpose of holding together jellyroll electrodes before inserting it into casing, after which no purpose. Battery manufacturers often test inactive parts for their physical parameters, i.e., elongation, water absorption, and temperature resistance. 1 However, chemical stability overlooked. Recently, was demonstrated polyethylene terephthalate (PET) can partially...
Cathode powders for lithium-ion batteries are typically made from hydroxide precursors with the intended transition metal composition and calcined a lithium source at high temperatures to make LiMO 2 , where M = Ni, Mn, Co. However, large amounts of process water salts like NaOH used in co-precipitation employed these 1 . Purifying drying after requires additional energy input produces waste streams that difficult treat, as illustrated Fig. 1a. In this work, we introduce simple, solvent-free...
Single-crystal LiMO 2 (M = 3d transition metal such as Ni, Mn, Al, and Co) has received much attention a positive electrode material over the last few years due to its superior cycling stability conventional polycrystalline materials 1 . Moreover, Co fallen out-of-favour of choice relatively high cost human rights abuses associated with mining 3 As well, synthesis requires complex co-precipitation equipment that not only increases manufacture, but also produces waste Na SO 4 Furthermore,...
As lithium-ion batteries (LIBs) have exploded in popularity due to the consumer electronics and electric vehicle industries, many resources are poured into research. While simplest cell format requiring least amount of active material make a research laboratory study various aspects is usually coin cell, it far from most representative commercial LIBs. Oftentimes, cells made with large negative electrode overhang reduce risk positive/negative misalignment, but region can cause Li + become...