In a previous story, I explored the critical pain points in lithium-ion battery cell production, focusing on the “magic triangle” of slurry formulation: dispersion, process conditions and carbon black properties. Let’s dive deeper into why achieving homogeneous slurries and defect-free coatings is such a challenge.
Why is formulating the perfect slurry is so challenging in lithium-ion battery cell production?
Formulating the perfect slurry is far from straightforward. It involves various ingredients, each with unique sizes, surface properties and amounts. Dispersing these ingredients might sound simple, but it’s actually a science. Dispersing goes beyond just mixing or blending. Even a well-executed dispersing process is often far from achieving maximum dispersion. It’s about achieving uniformity at a level that ensures consistency and stability, which is much more complex than simply blending the components together.
What makes the science of mixing so complex in lithium-ion battery cell production?
Many labs have mixing equipment, but determining the optimal speed, duration, device geometry and geometry of the blades for the best results is often a mystery. The system’s complexity, driven by numerous parameters, makes a comprehensive design of experiments approach impractical due to budget and timeline constraints. As a result, many empirical studies are conducted, relying on existing “working” procedures with some adjustments.
Time constraints and iterations
Development groups often face tight project timelines, making it challenging to optimize the system fully. Even after 10 to 15 iterations, performance might converge to a local maximum rather than a total maximum, without anyone realizing it. The only way to overcome these challenges is through collaboration, learning from experts and suppliers. This approach saves significant time, energy and costs.
Easy as cake? Not really
Think about preparing a cream cake. Pastry chefs have perfected their craft, but our first attempts often fall short in appearance, stability and taste. Only with support, training and process knowledge do we improve and, eventually, some secret ingredients are revealed.
Why is Orion S.A. uniquely qualified to make battery materials?
At Orion S.A., with more than 160 years of experience with carbon black, we understand the critical role this material plays in impacting rheology, while also incorporating various matrices in slurry formulation. Our global team is here to support you with engineered conductive carbon blacks, process optimizations, and deep technical insights that enable you to achieve high-performance electrodes and reduce scrap rates. Let’s connect and discuss how we can tackle these challenges together.
Dr. Michael Rohde is the director of Global Marketing for Batteries at Orion S.A. He earned a doctorate in chemistry from the University of Freiburg and an MBA from the Frankfurt School of Finance and Management.
HOUSTON – Carbon black has been used since ancient times in China and Egypt, yet today it remains a high-tech material worthy of scientific interest. This is due to the numerous ways it can be engineered to serve as an essential component in a variety of everyday products – from paint and textiles to tires, power cables and batteries.
From left to right, the authors of Orion’s “Carbon Black” guide: Werner Niedermeier, Arndt-Peter Schinkel, Hauke Westenberg and Ricardo Chavez.
The 104-page article is the most current and comprehensive reference about carbon black. It covers the material’s history, morphology and production processes. The paper also presents recent technical findings on sustainability, rubber reinforcement, coloristic properties, electrical conductivity and structure breakdown, among other topics. (For more details, see a summary on Orion’s website here.)
“Many of the products we take for granted would not be possible without carbon black – one of the most ubiquitous materials in modern life,” said Natalia Scherbakoff, chief technology officer at Orion. “We continue to discover new ways to use carbon black to improve the products we rely upon every day.”
The article’s authors include:
Werner Niedermeier, vice president of Innovation, Polymer Systems
Ricardo Chavez, innovation manager for Thermoplastics
Hauke Westenberg, innovation manager for Rubber
Arndt-Peter Schinkel, vice president Innovation, head of Modelling
For those who have a deep technical interest in carbon black, here is a summary of some of the latest findings included in the paper:
Reinforcement of rubber: Besides carbon black’s morphology, namely specific surface area (STSA) and structure (COAN), the surface energy or surface activity is recognized as a third important parameter, which plays a dominate role in the reinforcement of a rubber matrix. All tests so far indicate that the high-energy centers on the carbon black surface originate mainly from defects and edges of the basal planes and unorganized carbon atoms.
From left to right, the authors of Orion’s “Carbon Black” guide: Werner Niedermeier, Arndt-Peter Schinkel, Hauke Westenberg and Ricardo Chavez.
Coloristic properties: Carbon black dispersed in media — for example in plastics — imparts not only a certain blackness but also colors ranging from a bluish to a brownish black. This color range is referred to as the undertone or masstone of the black and is strongly correlated to light scattering. Calculations of the scattering intensity by using Mie scattering theory of particles of 50nm and 200nm can explain why the coloristic impression changes from blue to red for full-shade application and a tinting application.
Electrical conductivity: First, it must be mentioned that all carbon blacks are conductive due to their graphitic nature. The electrical conductivity imparted by carbon black is used in various applications — for example, for lithium-ion batteries, high-volage cables and fuel hoses. This article explains what is meant by an ultra-conductive carbon black and explains the impact of carbon black concentration, specific surface area, structure and dispersion on the conductivity in an application. The electrical conductivity of a carbon black filled compound depends strongly on the gap size between adjacent aggregates, meaning that direct contact between the aggregates is not necessary for establishing a conductive network.
Structure breakdown: It could be shown that an aggregate breakdown can be analyzed by applying aggregate-size distribution (ASD) measurements before and after exposing the carbon black to high pressures. A structure breakdown cannot be observed for standard ASTM grades such as N220 or N134. The breakdown of aggregates tends to occur in large aggregates. Hence, the probability of aggregate breakdown is higher for carbon black with a high OAN (> 150).
Sustainability: It was demonstrated by Orion that virgin furnace blacks can be produced using renewable plant-based-oil, tire pyrolysis oils and bio-circular feedstocks.
I recently read an excellent study by Dr. Florian Degen and Dr. Oliver Krätzig from the Fraunhofer Research Institution for Battery Cell Production.
The article in the Journal of Power Sources Advances highlights the critical pain points in lithium‑ion battery cell production — from elevated scrap rates and throughput bottlenecks to soaring energy demands. Notably, the mixing & coating step stands out as a key contributor to process inefficiencies and reject rates.
A model that shows how the super high structure of Orion’s carbon black makes long aggregate chains that form a conductive network in active materials.
This finding aligns perfectly with our experience at Orion S.A. The underlying challenge often boils down to the “magic triangle” of slurry formulation: dispersion, process conditions and carbon black properties. These pillars are inseparable and must be harmonized to deliver stable, homogeneous slurries and defect‑free electrode coatings.
Carbon black is often underestimated, largely because it represents only a small mass fraction of the cell. Yet its structure, surface chemistry and aggregate size distribution significantly influence slurry rheology and, in turn, cell performance.
If you’re scaling lithium-ion battery production or working on a new formulation for a project, let’s talk. Orion’s experts in your region are ready to partner with you. They deliver engineered conductive carbon blacks, process tweaks and deep technical insight to accelerate high‑performance electrodes. Contact us!
Dr. Michael Rohde is the director of Global Marketing for Batteries at Orion S.A. He earned a doctorate in chemistry from the University of Freiburg and an MBA from the Frankfurt School of Finance and Management.
New ECOLAR 50 POWDER delivers comparable performance to regularly produced specialty carbon blacks across a broad range of coatings systems.
HOUSTON – Orion S.A. (NYSE: OEC), a global specialty chemicals company, has launched ECOLAR 50 POWDER – an award-winning bio-circular carbon black that helps coatings manufacturers formulate more sustainable coatings.
“We’re leading the way in advancing carbon black to meet increasing industry demands for sustainable products,” said Tilo Lindner, vice president for global marketing for specialty carbon black at Orion, which more than 10 years ago was the first company to launch a plant oil-based carbon black product.
“ECOLAR 50 POWDER enables coatings formulators to develop truly sustainable products in all kinds of coatings applications,” Lindner added.
The product won a Ringier Innovation Award, which recognizes companies, technologies and products that have outstanding innovation and market influence. The recognition was celebrated at a ceremony on May 22 in Shanghai.
ECOLAR 50 wins a Ringier Innovation Award recognizing products with outstanding innovation and market influence.
Based completely on bio-circular feedstock not in competition with the food chain, ECOLAR 50 POWDER contains 100% biogenic raw material per 14C analysis. A low to medium color furnace black, ECOLAR 50 POWDER’s coloristic properties provide medium jetness in mass tone applications plus good tinting strength.
For example, when testing in a solvent–borne alkyd/melamine stoving enamel system, ECOLAR 50 POWDER achieved medium jetness at a higher level compared to other regular specialty carbon blacks. It also produced a comparable neutral undertone.
Tested In a water-borne 1K PU coating system, ECOLAR 50 POWDER produced jetness comparable to other regular specialty carbon blacks and generated a more neutral undertone.
Compared to traditionally produced low-color furnace blacks, ECOLAR 50 POWDER has similar wetting and dispersion properties and provides comparable coloristic performance for both full-tone and tinting applications.
When presenting the Ringier Award to Orion at the Shanghai ceremony, the judges said, “Orion perfectly combines environmental protection and performance. ECOLAR 50 demonstrates excellent environmental protection properties and functionality in coatings applications, providing a more sustainable solution for the coatings industry.”
For more information about ECOLAR 50 POWDER and the Orion portfolio for coatings systems, contact the Orion sales team here.
About Orion S.A.
Orion S.A. (NYSE: OEC) is a leading global supplier of carbon black, a solid form of carbon produced as powder or pellets. The material is made to customers’ exacting specifications for tires, coatings, ink, batteries, plastics and numerous other specialty, high-performance applications. Carbon black is used to tint, colorize, provide reinforcement, conduct electricity, increase durability and add UV protection. Orion has four innovation centers and produces carbon black at 15 plants worldwide, offering the most diverse variety of production processes in the industry. The company’s corporate lineage goes back more than 160 years to Germany, where it operates the world’s longest-running carbon black plant. Orion is a leading innovator,
applying a deep understanding of customers’ needs to deliver sustainable solutions. For more information, please visit orioncarbons.com.
Forward-Looking Statements
This document contains certain forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements are statements of future expectations that are based on current expectations and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in these statements. You should not place undue reliance on forward-looking statements. Each forward-looking statement speaks only as of the date of the particular statement. New risk factors and uncertainties emerge from time to time and it is not possible to predict all risk factors and uncertainties, nor can we assess the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. We undertake no obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information, other than as required by applicable law.
Carbon black is a solid form of carbon that comes in the form of powder or pellets. It’s an essential material found in many of the products we use every day. In fact, nearly every man-made product that is black contains carbon black.
What are common uses of carbon black?
This high-tech material is most commonly used to reinforce rubber, such as in tires and mechanical rubber goods like hoses, seals, and belts. In inks and coatings, carbon black serves as an excellent black pigment, producing a deep black shade. It also reinforces polymers, protecting them from the damaging effects of ultraviolet (UV) radiation from the sun. Additionally, carbon black helps conduct electricity in batteries, making it a versatile and ubiquitous material.
What are the chemical properties of carbon black?
Allow us to get a bit technical for the experts. Chemically, carbon black is a colloidal form of elemental carbon, similar to graphite in its microstructure. It is characterized by extremely small particles and a high specific surface area (SSA). Carbon black usually contains more than 95% carbon. Depending on the production process and the raw materials used, it may also contain small amounts of chemically bound oxygen, hydrogen, nitrogen, and sulfur. The physical and chemical properties of each grade of carbon black are kept within narrow specifications to ensure consistency and quality.
Why is carbon black important?
Carbon black’s versatility makes it crucial in various industries. For example:
Automotive: It strengthens tires and other rubber components, enhancing durability and performance.
Printing: It provides the deep black color in inks, ensuring high-quality prints.
Batteries: It improves the conductivity of batteries for electric vehicles, battery energy storage systems and dry cell batteries, contributing to better performance.
HOUSTON – Orion S.A. (NYSE: OEC), a global specialty chemicals company, announced today that the Reciend Group will be its distributor of Specialty carbon black product lines in Peru.
For more than 20 years, Reciend has been Orion’s agent and distributor in Colombia.
“We know the same dedication and technical work that transformed the Colombian market will be the key factors to drive the evolution for the coatings and plastics market in Peru,” said Eduardo Belisle, a technical business manager at Orion. “We look forward to supporting Reciend on this new journey.”
Alejandro Mejía, chief strategy officer of Reciend, said the collaboration is a strategic milestone that strengthens his company’s mission of bringing specialized solutions to Andean markets.
“It is an excellent opportunity to create even more value for our customers and principals through our talented team, committed to delivering high-performance solutions to industrial markets — such as coatings, plastics, printing systems and battery applications — where we have strong expertise and a broad ingredients portfolio,” Mejía said. “After decades of working with Orion’s carbon blacks, we’ve established a solid foundation, and now the expansion of our collaboration into Peru enables us to replicate that success in this important and growing market.”
About Orion S.A.
Orion S.A. (NYSE: OEC) is a leading global supplier of carbon black, a solid form of carbon produced as powder or pellets. The material is made to customers’ exacting specifications for tires, coatings, ink, batteries, plastics and numerous other specialty, high-performance applications. Carbon black is used to tint, colorize, provide reinforcement, conduct electricity, increase durability and add UV protection. Orion has four innovation centers and produces carbon black at 15 plants worldwide, offering the most diverse variety of production processes in the industry. The company’s corporate lineage goes back more than 160 years to Germany, where it operates the world’s longest-running carbon black plant. Orion is a leading innovator, applying a deep understanding of customers’ needs to deliver sustainable solutions. For more information, please visit orioncarbons.com.
Forward-looking Statements
This document contains certain forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements are statements of future expectations that are based on current expectations and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in these statements. You should not place undue reliance on forward-looking statements. Each forward-looking statement speaks only as of the date of the particular statement. New risk factors and uncertainties emerge from time to time and it is not possible to predict all risk factors and uncertainties, nor can we assess the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. We undertake no obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information, other than as required by applicable law.
Contact:
William Foreman
Orion S.A.
Director of Corporate Communications and Government Affairs william.foreman@orioncarbons.com
Direct: +1 832-445-3305
HOUSTON – Orion S.A. (NYSE: OEC), a global specialty chemicals company, announced today the European Commission has listed the company on its “Innovation Radar” website, which identifies high-potential innovators that have done EU-funded research.
The recognition highlights Orion’s achievement as a “Key Innovator” for being the first company to produce circular carbon black from 100% pyrolysis oil from end-of-life tires. The market-ready material serves as an alternative to carbon black made from fossil oil.
“Driving circularity is part of Orion’s long-term strategy,” Orion CEO Corning Painter said. “Our customers are increasingly relying on us to provide solutions to meet the growing demand for circular products. We are scaling up our capabilities to process tire pyrolysis oil and have other innovations in our sustainability pipeline focused on cost-effective solutions.”
Orion developed the circular carbon black recognized by the Innovation Radar as a partner in the EU-funded BlackCycle project (Horizon 2020 program under grant agreement No: 869625).
The award-winning BlackCycle initiative was led by Michelin and included seven industrial partners and five research and technology organizations, with the objective to design pioneering processes to make new tires from end-of-life tires.
“Although the BlackCycle project has concluded, our innovation work continues with other initiatives with circular carbon black that involve reducing our carbon footprint, improving yield and throughput, and potentially lowering material costs,” said Natalia Scherbakoff, chief technology officer at Orion.
Last year, Orion launched its “Clean Carbon Black Research and Development Project,” funded with a €6.4 million grant from the German government and European Union. The project is focused on developing a climate-neutral process for producing carbon black from alternative carbon sources.
Orion S.A. (NYSE: OEC) is a leading global supplier of carbon black, a solid form of carbon produced as powder or pellets. The material is made to customers’ exacting specifications for tires, coatings, ink, batteries, plastics and numerous other specialty, high-performance applications. Carbon black is used to tint, colorize, provide reinforcement, conduct electricity, increase durability and add UV protection. Orion has four innovation centers and produces carbon black at 15 plants worldwide, offering the most diverse variety of production processes in the industry. The company’s corporate lineage goes back more than 160 years to Germany, where it operates the world’s longest-running carbon black plant. Orion is a leading innovator, applying a deep understanding of customers’ needs to deliver sustainable solutions. For more information, please visit orioncarbons.com.
Forward-Looking Statements
This document contains certain forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements are statements of future expectations that are based on current expectations and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in these statements. You should not place undue reliance on forward-looking statements. Each forward-looking statement speaks only as of the date of the particular statement. New risk factors and uncertainties emerge from time to time and it is not possible to predict all risk factors and uncertainties, nor can we assess the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. We undertake no obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information, other than as required by applicable law.
Contact:
William Foreman
Orion S.A.
Director of Corporate Communications and Government Affairs william.foreman@orioncarbons.com
Direct: +1 832-445-3305
Among the highlights is a water-recycling project in drought-stricken South Africa
HOUSTON – Two years ago, a severe drought hit the Nelson Mandela Bay municipality on the southern coast of South Africa. Reservoirs were nearly empty, pushing the population of 1.3 million close to “day zero” when water stops flowing from the taps.
The region is home to an Orion S.A. (NYSE: OEC) facility that produces carbon black – an essential material for the country’s tire industry. The crisis inspired Orion to find a solution that would help the municipality conserve its precious water supply.
Despite significant engineering challenges, Orion built a water treatment system at its facility. The technology recycles treated effluent water from a nearby municipal sewage plant so that the water can be used in Orion’s production process.
“The potable water we once used to make our products is saved for the community,” Orion CEO Corning Painter said. “The treated effluent water that once got pumped into the ocean is now repurposed for an industry that makes carbon black, which enables car tires to last longer and perform better. Recycling the water will also lead to a substantial cost savings.”
Orion’s water treatment plant at its carbon black facility in Nelson Mandela Bay, South Africa.
The South Africa case study is featured in Orion’s “Sustainability Report 2023,” which the company released today with the theme: “Driving innovation, enabling the everyday.” The report covers a variety of highlights, including:
Achieving an EcoVadis Platinum Medal, positioning the company in the 99th percentile of companies evaluated.
Opening a Battery Innovation Center to develop new products and formulations for lithium-ion batteries driving the shift to electrification.
Investing €12.8 million – including €6.4 million in grant funding from the German government and European Union — to further develop and demonstrate a climate-neutral process for producing carbon black from alternative carbon sources.
Leading the carbon black industry in the number of production sites with ISCC (International Sustainability & Carbon Certification) PLUS certification.
Reaching the goal of having 80% of employees receive 40 or more training hours – double the average training hours in 2022.
In a Q&A section with Painter, the CEO describes how the company developed a reputation for being a leader in developing sustainable products in its industry.
“Our history of innovation and sustainability makes us the perfect disruptor,” Painter said. “We won’t overtake our bigger competitors by playing the same game. Making sustainable products is not only the right thing to do, it is also what customers want.”
In the report, the company unveiled its water-recycling project in South Africa. Orion is the only global company in the carbon black industry that has a site in Sub-Saharan Africa.
The project began in early 2023 and involved installing a 65-meter-long pipeline from the Orion site to the municipal water treatment plant. A horizontal-boring process was used to run the pipeline 5 meters under a road.
A 7-meter-deep sump had to be built for the system. This was a major excavation challenge because the sandy soil did not provide much solid ground. It was like digging a hole in a sand dune. But the team used sandbags to stabilize the ground and keep the hole from being filled with water.
Orion now has the capacity to recover 3 million liters a day from the municipal plant and treat the effluent water so that it meets the quality level for the site’s production process.
“With this project, we’re demonstrating our commitment to our company’s core values: accountability, innovation and building enduring relationships,” Painter said. “Finding an innovative solution to conserving water is one of the best ways we can strengthen our relationship with the community and improve supply security for our customers.”
The 2023 Sustainability Report can be found on Orion’s website here.
About Orion S.A.
Orion S.A. (NYSE: OEC) is a leading global supplier of carbon black, a solid form of carbon produced as powder or pellets. The material is made to customers’ exacting specifications for tires, coatings, ink, batteries, plastics and numerous other specialty, high-performance applications. Carbon black is used to tint, colorize, provide reinforcement, conduct electricity, increase durability and add UV protection. Orion has four innovation centers and produces carbon black at 15 plants worldwide, offering the most diverse variety of production processes in the industry. The company’s corporate lineage goes back more than 160 years to Germany, where it operates the world’s longest-running carbon black plant. Orion is a leading innovator,
applying a deep understanding of customers’ needs to deliver sustainable solutions. For more information, please visit orioncarbons.com.
Forward-Looking Statements
This document contains certain forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements are statements of future expectations that are based on current expectations and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in these statements. You should not place undue reliance on forward-looking statements. Each forward-looking statement speaks only as of the date of the particular statement. New risk factors and uncertainties emerge from time to time and it is not possible to predict all risk factors and uncertainties, nor can we assess the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. We undertake no obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information, other than as required by applicable law.
Contacts:
William Foreman
Orion S.A.
Director of Corporate Communications and Government Affairs william.foreman@orioncarbons.com
Direct: +1 832-445-3305
HOUSTON – Orion S.A. (NYSE: OEC), a global specialty chemicals company, today launched PRINTEX® chroma 500 BEADS, a high-jetness carbon black designed for the engineered plastics market that demands the highest aesthetic quality.
The new product is part of Orion’s continued investment in developing higher-value grades of carbon black. The beaded furnace black is also the start of a series of new specialty grades for the polymers market.
“PRINTEX® chroma 500 BEADS is a big breakthrough for Orion, offering an excellent balance between high jetness and dispersibility,” said Tilo Lindner, vice president of Global Marketing for Specialty at Orion. “This is a product our customers have been demanding for a long time. It’s ideal for injection-molded automative parts, household appliances, electronics and other applications with a shiny, glossy finish.
Orion can offer PRINTEX® chroma 500 BEADS with International Sustainability and Carbon Certification (ISCC PLUS), highlighting the company’s commitment toward a circular economy. Orion leads its industry with the number of carbon black production sites with the ISCC PLUS certification.
For more information about PRINTEX® chroma 500 BEADS, contact the Orion sales team here.
About Orion S.A.
Orion S.A. (NYSE: OEC) is a leading global supplier of carbon black, a solid form of carbon produced as powder or pellets. The material is made to customers’ exacting specifications for tires, coatings, ink, batteries, plastics and numerous other specialty, high-performance applications. Carbon black is used to tint, colorize, provide reinforcement, conduct electricity, increase durability and add UV protection. Orion has four innovation centers and produces carbon black at 15 plants worldwide, offering the most diverse variety of production processes in the industry. The company’s corporate lineage goes back more than 160 years to Germany, where it operates the world’s longest-running carbon black plant. Orion is a leading innovator, applying a deep understanding of customers’ needs to deliver sustainable solutions. For more information, please visit orioncarbons.com.
Forward-Looking Statements
This document contains certain forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements are statements of future expectations that are based on current expectations and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in these statements. You should not place undue reliance on forward-looking statements. Each forward-looking statement speaks only as of the date of the particular statement. New risk factors and uncertainties emerge from time to time and it is not possible to predict all risk factors and uncertainties, nor can we assess the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. We undertake no obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information, other than as required by applicable law.
Contacts:
William Foreman
Orion S.A.
Director of Corporate Communications and Government Affairs william.foreman@orioncarbons.com
Direct: +1 832-445-3305