我们认为当前锂电池有两大技术路线，以方形铁锂为代表的高性价比路线和以三元高镍大圆柱为代表的高性能路线。
-近两年，方形铁锂得益于CTP、刀片电池的技术进步，在续航里程600公里及以下乘用车市场性价比十足。根据鑫椤锂电数据，22年3月25日铁锂方形动力电芯均价为0.77元/wh，同期三元方形动力电芯均价在0.84元/wh。得益于刀片电池技术，比亚迪LFP版车型能量密度达140Wh/kg，续航里程达565km，突破了铁锂续航里程天花板。
-往后看，高镍+硅基负极+大圆柱三者优劣势互补主打高能量密度，更适配600公里续航以上市场。大圆柱的优势是不易热失控和弧形表面更耐膨胀。高镍三元优势是能量密度高，劣势是成本高+热稳定性差，成本高的改变可依赖三元一体化镍冶炼投放降低镍的成本，热稳定性差可搭配圆柱封装形式改善。硅基负极优势是能量密度高+适合快充，劣势是成本高+易膨胀，我们认为成本高是初期，可依赖规模化降本，易膨胀可搭配圆柱封装形式。
本篇报告系高镍+高电压+大圆柱“系列新技术报告——从硅负极说起新材料的投资机会，并引申出周边新材料投资机会，如单壁碳纳米管、补锂剂、PAA粘结剂，有望得以受益于低基数+渗透率提升，未来几年市场空间增速可观，得益于技术溢价，龙头利润空间有望可观。
Cost and performance factors: lithium-iron square vs high-nickel ternary cylindrical batteries
-In the past two years, cell-to-pack (CTP) and blade tech advances have made lithium-iron square batteries highly cost-effective for passenger cars with a cruising range of 600km and below. Lithium-iron square power cells cost RMB0.77/Wh on average as of 25 March 2022, according to Xinyu Lithium battery data, while ternary square power cells cost RMB0.84/Wh on average. Blade battery technology has broken through the lithium-iron range ceiling. BYD’s LFP model has an energy density of 140Wh/kg and a cruising range of 565km.
-High nickel, silicon anode and large cylinder technologies are complementary and their main focus is high energy density for the over-600km EV range market.
Large cylinders are less prone to thermal runaway and the curved surface resists expansion. High-nickel ternary provides high energy density but at high cost with poor thermal stability; these disadvantages could be managed with the use of integrated ternary nickel smelting to reduce nickel cost and a cylindrical pack could improve thermal stability.
Silicon anode offers high energy density and fast charging but at high cost and the risk of swelling; we believe the initial high cost could reduce with scale production and cylindrical packs would reduce swelling.
This report discusses investment opportunities in high-nickel, high-voltage and large-cylinder battery technologies: from silicon anode to derivative new materials like single-walled carbon nanotubes, lithium supplements and PAA binders. They would benefit from a low base and rising penetration as the market expands in the next few years. A considerable advanced tech premium would raise profit margins.
硅是负极材料进步的方向，放量在即。目前主流石墨负极企业比容量可做到355-360mAh/g，接近理论比容量372mAh/g，负极材料急需升级，硅材料理论比容量达4200mAh/g，是石墨的10倍以上。受制于膨胀率高（硅在300%，石墨在12%），硅负极产业化受阻，目前硅基负极主要应用在高端3C数码、电动工具、高端动力电池领域，在负极渗透率不足2%。特斯拉自产电池大圆柱明确表示采用硅负极，此外车企电池厂如松下、三星、广汽、蔚来等也宣布采用硅负极。
硅负极一般通过掺杂的形式到人造石墨中以实现产业化（目前掺杂比例在5%左右），根据硅材料选择的不同分为硅碳、硅氧两条技术路线。
-硅碳负极：采用纳米硅和石墨材料混合，目前商业化容量在450mAh/g以下，首效高，但体积膨胀系数过大，导致其循环差，一般在500-600周，一般用于消费电池。
-硅氧负极：采用氧化亚硅和石墨材料混合，目前商业化应用容量主要在450-500mAh/g，首效相对较低，但循环性能相对较好，既可用于消费也可用于动力。
Silicon leads the growth trend in anode materials and we expect volumes to increase. Mainstream graphite anode companies currently achieve specific capacity of 355-360mAh/g, close to the theoretical 372mAh/g. anode materials need to be upgraded urgently. The theoretical specific capacity of silicon materials could reach 4,200mAh/g, more than 10x that of graphite. Silicon anode roll-outs are hampered by high expansion rates (silicon 300% vs graphite 12%). Silicon anode applications are mainly found in high-end 3C digitalization, power tools and high-end power batteries, with a anode permeability of less than 2%. It appears that Tesla's proprietary large-cylinder batteries use silicon anodes. Battery manufacturers like Panasonic, Samsung, GAC and Nio have also announced they will use silicon anodes.
Silicon anodes are doped into artificial graphite to achieve commercialization (with the current doping ratio at about 5%) via two main routes of silicon-carbon and silicon-oxide, depending on which silicon materials are selected.
-Silicon-carbon anodes: a mixture of nano-silicon and graphite materials: the current commercial capacity is below 450mAh/g, initial efficiency is high but the swell volume coefficient is large, resulting in weak cyclicity of 500-600 weeks. Generally used in consumer batteries.
-Silicon-oxide anodes: a mixture of silicon-oxide and graphite materials: the current commercial capacity is 450-500mAh/g, initial efficiency is low but cyclical performance is good. Can be deployed in both the consumer and power industries.
硅碳负极的制备的核心在于球磨，硅氧负极制备的核心在于氧化亚硅的改性。正如硅负极有纯品和复合品的概念（我们所说的硅基负极指的是复合品），硅负极的制备也有两段工序，我们将其分为前端的纯硅制备和后端的与石墨复合，我们认为核心是在前端的纯硅制备。硅碳的核心是制备纳米硅，一般采用机械球磨法，硅氧的核心是制备氧化亚硅，且需要改性处理，一般采用化学气相沉积法（CVD）进行碳包覆。
硅基负极的单价、CAPEX明显高于石墨负极。石墨负极的价格一般在3-6万元/吨，据我们测算硅负极纯品价格一般在30-70万元/吨，复合品价格一般在8-12万元/吨。人造石墨负极一体化产能单万吨固定自产投资一般在2亿元左右，硅基负极的特别是前端纯品硅的单万吨固定资产投资一般在10亿元左右。
Manufacturing processes: the manufacture of silicon-carbon anodes centers on the ball milling process, while that of silicon-oxide anodes centers on silicon-oxide modifications. As silicon anodes comprise both pure and composite products (we focus on the latter), there are two preparation processes: making pure silicon at the front end and graphite compounds at the back end. The front-end pure silicon process forms the core, in our view. At the heart of silicon-carbon anode manufacture is the preparation of nano-silicon, which generally uses the mechanical ball milling method. At the heart of silicon-oxide anode manufacture is silicon oxides, which need to be modified. Generally, chemical vapor deposition (CVD) is used for carbon cladding.
Unit prices and capex: silicon anodes have much higher unit prices and capex than graphite anodes. Graphite anodes are priced at about RMB30,000-60,000/t and pure silicon anodes are priced at about RMB300,000-700,000/t by our estimates, while composite products are priced at about RMB80,000-120,000/t. Artificial graphite anodes’ integrated production capacities require FAI of about RMB200m per 10,000t, while silicon-based anodes, especially front-end pure silicon, require about RMB1bn per 10,000t.
硅负极目前处于行业发展初期，海外日本信越较为领先，国内贝特瑞研发、量产、客户端全面领先同行。
-海外：日韩企业在硅基负极上领先多是在专利层面，如日本信越化学硅氧负极专利数行业领先，但其主营半导体等，量的层面未见领先。
-国内：贝特瑞于2010年取得硅基负极材料的技术突破，并于 2013年实现批量出货，客户系松下、三星。贝特瑞产品持续更新迭代，高代产品比容量、首次效率明显领先同行。贝特瑞现有硅负极产能3000吨（我们预计为纯品），规划产能4万吨。而同行尚处于百、千吨中试线水平，未见大批量出货。
硅基负极放量为衍生材料带来放量契机，典型如单壁碳管、补锂剂、负极粘结剂。
-单壁碳管：可在材料内部形成发达网络，覆盖在硅颗粒表面并在硅颗粒之间建立高度导电和持久的连接，显著提升硅负极循环寿命。
-补锂剂：硅负极表面SEI膜的形成需消耗大量锂源，这使得硅基负极的首次效率显著低于石墨，石墨材料有5%～10%的首次不可逆锂损耗，而硅的不可逆容量损失达15%～35%，故硅负极一般需要搭配补锂剂使用。
-PAA粘结剂：对于充放电循环中具有极高体积膨胀的硅基负极，合理设计粘结剂可大大改善其循环寿命。
前文以硅基负极为主线，衍生出单壁碳纳米管、补锂剂、PAA粘结剂，25年硅负极市场空间有望达300亿+，其他材料有望在50亿左右，21-25年复合增速在100%左右。
The silicon anode industry is currently in its early stage of development; Shin-Etsu Japan has the tech edge in the global market, while BTR New Energy is ahead of the China pack in terms of R&D, mass production scale and customers.
-Global: Japanese and Korean companies lead the global arena in silicon-based anodes and this is mostly due to their patents. Shin-Etsu Chemical holds the most silicon-oxide anode patents, but its core semiconductor business volume is not the largest.
-China: BTR New Energy made a tech breakthrough in silicon-based anode materials in 2010 and achieved mass shipments in 2013. Its customers include Panasonic and Samsung. BTR’s product upgrades and iteration have enabled its high-tier products to outperform peers on specific capacity and initial efficiency rates. The company has a 3,000t silicon anode production capacity (likely pure products) and planned capacity of 40,000t, while its peers are struggling to reach 100-1,000t capacities and have yet to achieve large-scale shipments.
The high silicon-based anode market volume brings opportunities for high-volume derivative materials, such as single-wall carbon tubes, lithium supplements and anode binders.
-Single-walled carbon tubes: a well-developed network is formed within the material, covering the surfaces of silicon particles to establish highly conductive and durable connections between silicon particles. This improves the life-cycle of silicon anodes considerably.
-Lithium supplements: the formation of SEI film on the surfaces of silicon anodes requires a large amount of source lithium, which weakens the initial efficiency of silicon-based anodes vs graphite ones. Graphite material has an initial irreversible lithium loss rate of 5-10%, while irreversible capacity loss in silicon materials is 15-35%. Hence, silicon anodes need lithium supplements.
-PAA binders: as silicon-based anodes are subject to significant swelling during charge and discharge cycles, so well designed binders are necessary to improve their life-cycle.
We have discussed silicon-based anodes derived with single-walled carbon nanotubes, lithium supplements and PAA binders. We expect the silicon anode market to amount to over RMB30bn in 2025E, while other materials markets could reach about RMB5bn; we expect a CAGR of about 100% over 2021-25E.
21年负极全球产量88万吨，预计21-25年锂电池复合增速40%，硅基负极渗透率我们预计在23年迎来放量拐点达6.5%，25年达14%（渗透率的假设和大圆柱放量相匹配）。单价硅纯品价格和人造石墨价格按照加权平均而得，纯品硅掺杂比例22年在5%，预计25年达8%，纯品硅价格22年在45万元/吨，25年降至30万元/吨，人造石墨22年在6万元/吨，25年降至4万元/吨，则硅基负极（复合品）22年单价在8万元/吨。25年降至6.1万元/吨。基于以上逻辑和假设，我们对四大新材料25年市场空间、龙头公司利润空间预测如下：
-硅基负极：全球需求量达52万吨，市场空间319亿元，21-25年复合增速135%。我们预计龙头系贝特瑞，市占率达40%，20%净利率下利润空间在19亿元。
-单壁碳管粉体：全球需求量达524吨，市场空间42亿元（多壁市场空间在200亿），21-25年复合增速153%。我们预计龙头系天奈科技，市占率50%，40%净利率下利润空间在7.3亿元。
-补锂剂：全球需求量达1.8万吨，市场空间44亿元，21-25年复合增速157%。我们预计单吨净利润25年在5万元（对应17%净利率），市占率在50%下，利润空间在4.8亿元。
-PAA粘结剂：全球需求量达5.1万吨，市场空间54亿元。21-25年复合增速94%。我们预计龙头30%净利率（茵地乐毛利率60%），市占率在50%下，利润空间在8.4亿元。
Global anode production amounted to 880,000t in 2021. We expect a lithium battery CAGR of 40% over 2021-25E, with silicon-based anodes penetrating 6.5% of this market in 2023E and 14% in 2025E (our permeability assumptions correspond to large-cylinder packs). With unit prices of pure silicon and artificial graphite based on weighted average, we forecast a pure silicon doping ratio of 5% in 2022E and 8% in 2025E. 2022E and 2025E price forecasts: pure silicon prices could reach RMB450,000/t in 2022E, then fall to RMB300,000/t in 2025E; artificial graphite could reach RMB60,000/t, then fall to RMB40,000/t; and silicon-based anodes (composites) could reach RMB80,000/t, then drop to RMB61,000/t. Based on these assumptions, we forecast market sizes and company profit margins in 2025E:
-Silicon-based anodes: global demand could grow to 520,000t and the market could generate RMB31.9bn at a CAGR of 135% over 2021-25E. We project Chinese leader BTR New Energy will hold a market share of 40%, a 20% net profit margin and RMB1.9bn profit potential in 2025E.
-Single-walled carbon tubes: global demand could reach 524t and the market could generate RMB4.2bn (with a multi-walled market size of RMB20bn) at a 153% CAGR over 2021-25E. We expect leader Jiangsu Cnano Technology will hold a market share of 50% on a profit potential of RMB730m on a 40% net profit margin.
-Lithium supplements: global demand could reach 18,000t and the market could generate RMB4.4bn, with a CAGR of 157% over 2021-25E. We expect net profit at RMB50,000/t (with a 17% net profit margin), a market share below 50% and profit potential of RMB480m.
-PAA binders: global demand could reach 51,000t with a market size of RMB5.4bn on a CAGR of 94% over 2021-25E. We expect the market leader to have a net profit margin of 30% (with Indigo’s gross profit margin at 60%), a market share below 50% and profit potential of RMB840m.
